Sign of the times? Side-by-side foreclosures in Massachusetts. (Photo: Yovani via Flickr)

Similarly, government policies such as low gas tax rates and import protections on light trucks encouraged the development of a bloated domestic auto industry focused on the production of inefficient SUVs.

When high oil prices and deep recession then threatened to push General Motors and Chrysler into bankruptcy, leading to hundreds of thousands of lost jobs, the government felt it had no choice but to step in to keep the companies afloat.

Now the government owns large stakes in companies that will only profit if the American public goes car-buying crazy over the next few years.

The list goes on. The economic crisis that currently afflicts us has made it clearer than ever that we need to change the way we do many things, but because the economy is in such difficult shape, it is hard to pursue anything other than policies designed to keep the economic engine from stalling out completely. Big transitions must wait for later.

Can the same be said for sprawling urban development? Have government interventions essentially bailed out the very places that proved most vulnerable amid oil shocks and housing busts?

Chris Leinberger argued that very point in a recent blog post at The New Republic's Avenue:

While there is no federal or private ... dataset that identifies where exactly in metropolitan areas the most mortgage defaults are, local analyses and some news reports indicate the bulk of the problem is on the fringe...Thus, some of the biggest beneficiaries of federal efforts to stem foreclosures and keep families in their homes are those located in exurbia.

He has a point. Foreclosures have been concentrated on urban fringes, so federal efforts to modify mortgages and otherwise reduce defaults have tended to direct more aid to exurbs than inner suburbs and city centers. In addition, rates of home ownership and car ownership are higher in the suburbs than in city centers, so federal housing subsidies (including the new home-buyer tax credit and low interest rates generally) and automobile subsidies ("Cash for Clunkers") have had a geographic bias toward suburbanites.

To a certain extent, this has been unavoidable. Most Americans live in auto-oriented areas in suburban places, and a large share of those Americans are facing financial difficulty. Any measure that helped stressed households, including checks of equal value cut to all workers, would tend to benefit suburbanites more than urban dwellers.

One should also be careful not to oversell the value of the interventions. Efforts to reduce foreclosures have actually had pretty depressing results.

But certainly the government might have done things differently -- and pursued policies designed to help households as much as possible -- rather than those aimed at keeping households in homes they couldn't afford, or moving families into homes in unsustainably sprawling locations. So it's important to ask: What can we expect for exurban areas and how will the government's policy choices affect them?

First, it's important to understand the dynamics of the bubble. For a number of reasons, among them low interest rates and innovations in mortgage finance, the residential real estate market began to experience a boom at the beginning of this decade. This energy in housing markets manifested itself in different ways in different places.

In areas where housing supply was tight -- where it was not easy to respond to increased demand by building more -- prices rose sharply. In areas where housing supply was more elastic, prices rose some, but construction exploded. In general, it's tough to build in dense center cities, and easy to build on the low-density fringe.

As a result, rising housing demand led to construction on the urban fringe. It also led to higher prices in center cities, which pushed many low- and middle-income families to move to places with cheaper housing markets, which increased demand for homes on the fringe and led to even more construction. Rising demand for exurban living led to construction of exurban housing, and rising demand for urban living led to construction of exurban housing.

When the crash came, it quickly became apparent that housing inventory on the fringe had grown out of all proportion to the actual demand for such housing. Meanwhile, there continued to be excess demand for homes in center cities.

So while the bust ended up being painful for everyone, it was far less painful for urban centers. In those places, price declines brought in buyers, helping to keep inventory down and price declines orderly.

In exurbs, by contrast, falling prices went hand in hand with huge numbers of vacancies. Prices fell chaotically and dramatically as inventory overhang led to falling home values, which contributed to foreclosures, which added to inventory, which further depressed home values and led to still more defaults and foreclosures.

Another way to say this is that center-city housing markets experienced a correction, while exurban housing markets entered a vicious cycle leading to wrenching housing price declines that will likely push prices below replacement costs in some areas.

This is a dangerous place for neighborhoods to be. Vacant homes will begin to deteriorate, and occupied homes unlikely to sell for more than replacement costs (or more than the value of the owner's mortgage) will suffer from disinvestment. The housing stock will become second-rate.

As neighborhoods fall apart, wealthier and more mobile homeowners will move away, while excess inventory and rock bottom prices will attract low-income households. The tax base will fall and so services will decline, and the general desirability of such areas will drop. Some, and perhaps many, of these neighborhoods will become slums.

How do we know? Well, this is a storyline we've seen before, both in center cities during the decades of urban decline and in depopulating Rust Belt cities for much of the past half century. It is a process that is very difficult to reverse.

And in some ways, suburban slums may be far worse for the poor than the previous urban version. In center cities, density and public transit provide a basic level of mobility for the working poor; in suburbs, by contrast, lower income families cannot survive without an automobile. And even with massive suburbanization, inner-city decline could never entirely escape public attention, thanks to lingering employment concentrations in center cities, as well as historical and cultural attractions there. As a result, there was always some pressure for renewed investment in center cities.

But suburban neighborhoods are relatively remote; the very idea of the places is that residential neighborhoods remain well away from employment concentrations and other destinations. Remoteness may well allow suburban slums to decline in obscurity.

These changes will not be universal, just as previous decline in urban centers was far from universal. Rich suburbs will likely stay rich, and denser suburban areas may well experience great success by shifting to greater walkability and density. But many suburban neighborhoods may find themselves in circumstances that once characterized urban slums -- poverty, deteriorating services, failing schools, and rising crime.

Given all of that, how do the federal government's assistance programs measure up? Not particularly well, unfortunately.

The mortgage modification programs have primarily been oriented around keeping people in their homes (and loans). These have generally not been that successful; a surprisingly large number of modified mortgages still wind up in default. Keeping families who cannot afford their loans in their homes is likely to be bad for the families themselves and may lead to disinvestment, as those homeowners will continue to be cash-strapped and may suspect that they'll be unable to sell the home for more than the value of their mortgage.

Meanwhile, the housing tax credit is tailor-made to get relatively low-income buyers -- and first-time buyers -- into suburban homes. That's the intent; the thinking is that bringing buyers into the market will support prices and end the cycle of decline.

But this effort may well fail. Housing inventory in hard-hit neighborhoods is too substantial to be much reduced by an $8,000 credit (particularly one put in place when one-fifth of the population is under- or unemployed). And by encouraging lower income families to move to these neighborhoods, the government may actually be accelerating the process of decline. Higher income families already in those areas may not be willing to stay alongside the newcomers, and their departure will reduce the tax base.

In short, the government isn't just subsidizing sprawl. It's subsidizing the deterioration of sprawling areas.

What should the government be doing? Well, for starters, it should recognize that the housing crash has meant an increase in the relative price of center city homes, which were already unaffordable for many families before the bust. It is important to provide opportunities for affordable center city housing (for its own sake, and to reduce the rush of lower-income families to the fringe), and that means encouraging construction in center cities.

In particular, since it is clear that safe, walkable neighborhoods are in very high demand and are therefore holding their value well, it is important to build more such places.

Next, the government needs to stop subsidizing home ownership and focus on increasing mobility. Home ownership in an area where prices are declining is an anchor on a household. It can trap families in declining neighborhoods or in metropolitan areas where jobs are scarce. If keeping struggling owners in their homes is a priority, then policy should focus on getting them out of their loans and keeping them there as rent-paying tenants.

Third, government officials should learn the lessons of urban decline -- particularly that allowing the decline of the tax base to lead to an erosion in service quality will create negative social outcomes that will be very difficult and costly to address in the future. Once poor schools and high crime levels become the norm, it will take years and overwhelming investments to turn things around. It will be better for all involved to step in and continue to support services in deteriorating neighborhoods.

And finally, policy should focus on improving physical mobility and urban design in these places, for two reasons. First, greater mobility -- including walkability and transit access -- will be of great use to poorer families which may have irregular or no access to an automobile. And second, efforts to improve the design and connectivity of these communities will make them more attractive and less likely to suffer from complete collapse.

The problem is that these represent substantial changes -- a transition away from the prior way of doing business -- and it is difficult to do anything other than keep fingers in the dam at this point. This is understandable.

But with our approach to the housing crisis (and to the crisis of home and transportation affordability generally) as with the banking crisis and the crisis of consumer spending, and so on, the problem is clear -- putting out the fire is not enough. Absent real reform in banking, another crisis will hit us, and soon. Absent an increase in savings rates, over-indebted households will paralyze the American economy.

Without addressing the serious imbalances in the way we plan and build our communities, we can expect a serious, long-term crisis in exurban neighborhoods. It took us 40 years to begin to get declining urban centers back on the right track. Do we really want to repeat that experience?

Steven Rattner (Photo: WSJ)

Rattner was there to speak on the topic of the administration's automobile bailout and rehabilitation strategy. He was hopeful but realistic; he recognized that General Motors and Chrysler face an uphill battle, but he believes that the government was able to do enough to give the firms a shot at returning to profitability.

Why that should be a concern of the government is another question altogether, and it's not one with which Rattner really engaged. Understandably, I think, the administration agreed that GM and Chrysler really shouldn't be allowed to fail in the depths of recession.

And then I believe they determined that if they were going to keep propping up the companies, they ought to at least shepherd them through a balance sheet-clearing bankruptcy and reorganization, in the hopes that the companies might eventually make money.

But what Rattner was careful not to address was this: Saving the car companies will not protect American automakers' market share, will not save the city of Detroit, and will not really save that many jobs.

The line I quote in the first paragraph was made in the context of an argument about annual auto sales, and why sales totals are likely to return to levels typically observed before the recession. Sales of light vehicles grew to a peak of 17 million in 2005 before declining and then plummeting to their current level, in the neighborhood of 9 million (save for the month of August, thanks to "cash for "clunkers).

According to Rattner, GM will break even at a level around 16.5 million car sales. Maybe we'll get there. Population continues to grow.

On the other hand, households may find themselves holding on to automobiles longer (particularly since household debts may remain a problem for the next decade). They may also find themselves buying fewer cars. America is aging, and households with retirees may not want a car for each commuter. More families might opt for one vehicle, and use car-sharing services when another vehicle is necessary.

But now we find ourselves in a world in which GM shareholders -- among which number you and me and every other taxpayer -- need sales to move above 16.5 million to get the company back to profitability. That's a strange place for us to want to be.

If, given the option to buy as many automobiles as they want, Americans choose to buy fewer than they did before, we should cheer. Cars are expensive and largely used as production goods rather than consumption goods -- people buy them because they need them to do other things, like work and buy food. If they then find that they don't need them as much, a lot of revenue is freed which can be used on debt service, health care, better food and homes, education, and entertainment goods.

A world in which Americans are as happy with one car or no cars as they are with two or three is a better one, just as a world in which companies can produce more goods with less energy or machinery is a better one.

The transition is a difficult one for workers in the automobile industry who find themselves needing a new line of work, but nothing in the reconstitution of GM and Chrysler will change that. Manufacturing processes continue to become less labor-intensive. That's a technological trend that the government is powerless to reverse. The question, then, is how best to facilitate transitions into new fields.

And here, the bailout looks somewhat counterproductive. Today a shuttered car plant in Delaware will be converted for use by a producer of electric vehicles. The decline of GM opens up production possibilities for other enterprises, and the impeding of that decline frustrates them.

It also prevents policymakers from seeing beyond the automobile. As David Alpert wrote yesterday (and Sarah Goodyear noted today):

I've been meeting with elected officials in the region about transportation and development issues. One representative from Montgomery County recently expressed a general sentiment among area leaders that "we have to do something" to accommodate increased traffic between the American Legion Bridge and I-270. After all, Virginia is building HOT lanes that will bring more cars onto the Beltway, and Maryland is pushing for more lanes on 270 north of Rockville. Logically, this person said, the state and the county will probably have to connect the two with additional HOT lanes through Potomac and Bethesda.

Later in the conversation, when discussing Gaithersburg West, I noted the potential for biotech development at White Oak. That location is already a life sciences hub. It's closer to both DC and Baltimore, reducing the likely commutes for people working there versus Gaithersburg West. It's also in a part of Montgomery County with far fewer jobs than people, unlike the 270 corridor.

What it lacks, like Gaithersburg West, is good transit. There is an inactive proposal to build a Purple Line spur up New Hampshire or Route 29 to the area. Why not revive the idea? When I brought it up, the representative jokingly said something like, "I'd like some of what you're smoking." And in fact, with many transit projects including the Purple Line, Baltimore Red Line, and Corridor Cities Transitway already vying for funds, it would be very difficult to add a Purple Line spur to White Oak.

That's the conventional wisdom among most elected officials. We "have to do something" to add road capacity. But transit projects are so difficult as to be nearly laughable. Yet freeway projects are not cheap. As we saw from ACT's alternative plan for the I-270 corridor, you can build a lot of transit for the price of some freeway lanes. It's just that leaders are too accustomed to viewing road capacity as a necessity and transit as a luxury.

There is a terrible chicken-and-egg problem to transportation planning, in which planners express regret that there is so little transit demand and so much traffic before building new roads. They have to accommodate the demand they've got! But you can't have transit demand if you don't have transit, and if you don't recognize that, then you're doomed to keep building roads forever. No one in the mind of the planners has yet invented a substitute for the automobile.

But of course, that's not true. There are many substitutes for the personal auto. And now that households seem to be warming to them, the government finds itself looking at the shift as a problem to be solved, rather than a welcome trend to be encouraged.

It's fine to try and alleviate the pain of a major economic transition, but if officials don't understand that the transition is just that, and not a temporary slump, they may attempt to turn the palliative into a barrier to change. If you think there's no substitute for the automobile, then the decline of the auto industry looks like running headlong off a cliff.

But in reality, there is something just fine on the other side of the transition: a world in which people drive less and don't mind it. Maybe officials blind to that possibility will eventually stumble into it nonetheless. It would be much better for all concerned -- including those dependent on the auto industry for their welfare -- if the government managed to see it and chart a course for it.

To give an idea of the errors in his work, Glaeser made no allowance for population growth, and he assumed that the sole land use effect of high-speed rail would be to shift 100,000 suburbanites to the central city in both Dallas and Houston.

But these are absurd assumptions. The Census Bureau projects that America's population will grow by 130 million by mid-century, and the National Academies' Transportation Research Board estimates that America will add anywhere from 60 million to 100 million households in coming decades -- nearly doubling the current number of housing units.

This suggests that there is enormous potential ridership growth in growing metro areas and large opportunities for land use shifts. But Glaeser pretends that the world will be more or less static in coming decades.

For these reasons and others like them, I'm not very happy with this week's statement by Brookings' Jonathan Rothwell that "Glaeser’s core approach is sound," and that Rothwell's analysis of high-speed rail numbers "focus[es] on just those aspects of Glaeser’s analysis which merit criticism: the interest rate and the costs per passenger."

This is far too kind to what Glaeser himself said was back-of-the-envelope and which should not be interpreted to "represent ... a complete evaluation of any actual proposed route."

Still, even Rothwell's limited analysis of Glaeser's model (see below chart), using conservative but more appropriate data points for cost per passenger and interest rate, shows that high-speed rail systems are very likely to be worth the investment.

(Chart: The New Republic's Avenue)

Where Glaeser's data choices show construction of a Houston-Dallas rail line to be a money loser to the tune of $375 million, Rothwell's show net benefits of $122 million for the same line. The figures for a hypothetical Los Angeles-Las Vegas line are better still -- and one assumes that lines which are actually top-priority HSR corridors would perform significantly better.

Rothwell's estimates do not include environmental benefits, nor do they attempt to take into account changes in land use. They don't question other numerical assumptions of Glaeser's, such as his estimate of the value of time for business travelers (which might, by itself, shift promising lines into profitability). And as Rothwell notes, his numbers -- while different from Glaeser's -- are still pretty conservative.

In fact, any decision to build high-speed rail should focus on more than just the direct benefits to riders adjusted for environmental externalities. But just in case rail supporters were concerned that, if forced to argue on those terms, they would have difficulty pushing back against the Glaeser analysis, fear not -- his is hardly the last or best word on the issue.

Virginian rivals Creigh Deeds (D, at right) and Bob McDonnell (R, at left) (Photo: News Advance)

And to an extent, this may be right; Democratic voters are worn out from last year's presidential campaign and anxious to see real legislative progress, while Republican voters are increasingly fired up.

But there are real policy issues at stake in the race, of which transportation is among the most important. The state of Virginia has been among the country's fastest growing in recent years, and growth has concentrated in its metropolitan areas, particularly the northern suburbs outside Washington D.C. and the Hampton Roads area around Norfolk.

The state has grown by upwards of 10 percent since the 2000 Census -- by more than 800,000 people -- and most of that growth has taken place in the D.C. suburbs, the Norfolk area, and Richmond.

Meanwhile, infrastructure has not remotely kept pace. Virginia's gas tax rate is lower than most of its neighbors', and few of the state's roads are tolled. Consequently, funding has remained in short supply for most of the last decade, and the state's politics have focused on how to raise additional revenue without increasing taxes -- an unacceptable strategy in the Republican-controlled House of Delegates.

What this has meant is a series of ludicrous, roundabout means for bringing in money. Virginia tried imposing "abusive driver fees" of up to $3,000 per infraction, but the legislature ultimately repealed the measure in response to public outcry. The legislature later tried delegating the authority to tax to regional bodies, like the Northern Virginia Transportation Authority, but this was ultimately deemed unconstitutional.

Meanwhile, congestion in the Washington area has grown [PDF] by more than in any other metropolitan area in the country.

And so the 2009 gubernatorial election between McDonnell and Democrat Creigh Deeds has focused in no small part on how the candidates intend to address this ongoing crisis. The Washington Post's endorsement of Deeds paid special attention to the issue:

Mr. Deeds has run an enormous and possibly fatal political risk by saying bluntly that he would support legislation to raise new taxes dedicated to transportation. It is a risk that neither Mr. Kaine nor Mr. Warner felt they could take. But given that the state has raised no significant new cash for roads, rails and bridges in 23 years, Mr. Deeds's position is nothing more than common sense. It is fantasy to think that the transportation funding problem, a generation in the making, will be addressed without a tax increase. A recent manifesto from 17 major business groups in Northern Virginia, calling for new taxes dedicated to transportation, attests to that reality.

Ezra Klein notes that Deeds has tried to turn his willingness to accept new taxes into a mark of seriousness, credibility, and leadership. But, as Klein says, this may not pay off:

One of the problems with talking about taxes is that the benefits are left maddeningly unspecific. But little is more concrete in the average voter's life than his or her commute. How much more would the average Virginian pay in taxes to shave 10 minutes off the morning drive? Five minutes? What about making it more reliable, so there were fewer days when the Metro didn't come for 13 minutes?

I'd bet good money that most voters would pay a lot more than is being asked, at least if they genuinely believed the benefits would materialize. But there's nothing on Deeds's site indicating the concrete improvements expected from his plan. It all sounds good, but it's also quite vague. That's how politicians often are when talking about taxes, and it doesn't make much sense. Best Buy doesn't tell you the price before they show you the TV.

There are two good reasons why a politician might feel that it's necessary to limit promises on the subject of transportation improvements. One is that it is basically impossible to deliver on promises to reduce congestion unless one is willing to introduce congestion pricing on a wide scale.

Virginia has been working to introduce high-occupancy tolling lanes on freeways in the D.C. suburbs, but those plans have recently been scaled back. While lane construction on the Capital Beltway will continue, planned work to bring HOT lanes to I-95 has been postponed, based on some local community concerns and funding issues.

A major part of the problem is that leaders are unwilling to simply toll existing lanes. Rather, they feel that political acceptance of tolling will only come if new lanes are built, such that free lanes can exist alongside tolled lanes.

To a certain extent, this tolling method may be an unavoidable part of the move to congestion tolling. And having free-flowing tolled lanes alongside jammed free lanes may make the connection between tolling and free-flowing traffic clear.

But in the short run, this toll-new-lanes strategy makes the adoption of tolling a challenge, as governments have to spend quite a bit of money to get the projects up and running. The tolling of existing lanes is a matter of millions of dollars. New, tolled lanes are a matter of billions of dollars. And Virginia doesn't have billions to spare.

And so Deeds can't promise freedom from congestion, because he can't deliver it. The battle to win people over to congestion pricing is still being fought.

Deeds may also be reluctant to promise anything because at the moment he has no idea what the federal transportation law will be for most of his term. Any bold measure will require federal assistance (and often, the assent of both the federal and local governments). I don't doubt that Deeds would love to promise better Metro service -- or even better, additional transit expansion in the Washington area and around Hampton Roads. He'd probably love to promise faster and more frequent rail service.

But these are promises he just can't honestly make without knowing how much money will be available from Washington and what rules will apply to that money.

There are two things that I hope Washington, and particularly the Obama administration, will learn from this. The first is that to sell the increased revenue measures that must be a part of any transportation bill, you have to connect them to tangible improvements. Like Virginians, Americans don't mind paying higher taxes and want to see a better transportation system. But if you want to get the former, you have to help people see how it will produce the latter.

If you can't help voters visualize this connection, then it will be difficult to raise the necessary revenue.

How to make that connection? I obviously think that national leaders can begin shifting the frame on congestion pricing fast enough. It is economically, environmentally, and politically imperative that drivers begin to understand that user fees are a necessary part of building and maintaining transportation infrastructure.

I also think it will be important for the next federal transportation bill to enable construction of some grand projects. High-speed rail is a nice start. But as important as resurfacing roads and shoring up bridges is, we all want to be able to say that increasing these taxes or those fees will mean that millions more people will have access to reliable transit service the next time gas prices cross $4 per gallon.

And the second message I want Washington to hear is that transportation funding is a way to maintain local political energy for broad progressive goals, and in doing so to protect progressive politicians.

Creigh Deeds' campaign is a mess. Bob McDonnell has attacked pending climate legislation in Washington and accused Deeds of aiming to kill jobs with his tax-loving ways. Feeling cornered, perhaps, Deeds has back-pedaled on the issue and more or less taken the McDonnell line -- he, too, will oppose any new "energy taxes" coming from Washington. And meanwhile, the president is offering scant support for Deeds; he may well be unwilling to lend his name to what he sees as a doomed run.

One can imagine an alternative scenario, in which the president, having articulated a clear strategy on transportation and having embraced clean transportation measures in the climate bill, stumped hard for Deeds, spelling out just what money Virginia could expect from the legislation, which projects would benefit from that money, and how local economies would be buoyed by the immediate infrastructure spending and the better overall operation of the transportation system.

That would be an aggressive and proactive campaign -- one that connected issues of local importance to broader economic and environmental priorities, boosting local candidates and offering local activists a way to become invested in federal legislation.

The timing of this election was such that the above strategy may simply not have worked. Obama, and the Congress, are focused on health care.

But 2010 will be a different story. Obama won't be on the ballot, but his standing will loom large in many races. If Democratic voters are still feeling unexcited or ambivalent next year, then the Democratic majority will shrink and it will be more difficult than ever to pursue greener policies.

To motivate voters, it's important to connect tangible local issues with the broader progressive goals that excited much of the country in 2008. Energy, planning, and transportation issues offer a means to do that.

Deeds is fighting alone, unable to articulate a clear message, and unwilling to support important environmental priorities. And he will probably lose, because too few Virginians can understand why they ought to be energized by this campaign. And that will mean a dedicated road builder as the governor in Richmond.

If there isn't a better story being told next year, and if Washington isn't helping local officials tell a better story, the best chance America has had in decades to place the economy on a firm and sustainable foundation will be lost.

What's good for the driver in the middle is also good for public health. (Photo: FHWA)

Take performance parking. Both urbanists (and drivers) seem to believe that it's good (or bad), because it makes parking more expensive, which is bad (or good) for drivers. But this assumes that a free parking system, where open spots are almost never available, is desirable for drivers.

That's like saying that a store that gives away bread for free -- and which subsequently never has any bread -- is good for people who like eating bread.

For the most part, thinking about congestion pricing follows this same rule. Urbanists tend to like it because it makes driving more costly and raises revenue for transit infrastructure. Drivers tend to oppose it, because they don't want to pay more to drive. In fact, congestion pricing would be good for people who really want to drive and good for people who'd like to have an alternative to driving.

This message has been slow to sink in, but the fact that drivers may benefit from congestion pricing may be beginning to resonate with urbanists. Unfortunately -- and so powerful is the what's-bad-for-drivers-is-good-for-cities mentality -- the absorption of this message has caused some urbanists to conclude that they've been wrong all along, and that congestion pricing really is bad. If drivers might benefit, it must be the case that cities, and the earth, will not.

So writes the New Yorker's David Owen, in an extremely misguided piece in the Wall Street Journal.

By requiring car drivers to pay a fee to drive in a city at peak hours, congestion pricing reduces traffic and raises money that can be used to support public transit—both worthy goals.

Yet congestion pricing has dubious environmental value. Traffic jams, if they’re managed well, can actually be good for the environment. They maintain a level of frustration that turns drivers into subway riders or pedestrians.

He is saying that congestion pricing is a bad idea, because traffic encourages drivers to switch to transit or otherwise get off the roads. But this misses the point that congestion pricing works by ... encouraging drivers to switch to transit or otherwise get off the roads. And as a bonus, it creates revenue which can be used to build more transit alternatives for frustrated drivers.

Owen seems to be arguing that the primary effect of congestion pricing may be to spread driving out over a longer period of time rather rather than to encourage a shift away from driving. But of course, the primary effect of congestion might also be to spread driving out over a longer period of time rather than to encourage a shift away from driving, particularly in places that don’t have good transit systems (which makes the revenue question all the more salient).

The argument doesn't make sense, and it doesn't appear to be supported by actual experience with congestion pricing schemes, as Charles Komanoff points out here. In London, better driving conditions after the adoption of a congestion pricing regime encouraged some drivers to take additional trips, but that increase didn't come close to offsetting the drop in vehicle trips induced by the cordon charge.

As difficult as it may be for all involved to accept, congestion pricing manages to benefit transit riders and drivers. Commutes are faster and emissions are reduced. But the benefits don't stop there.

A new economics paper by Janet Currie and Reed Walker explores what happened to neighborhoods near congested highway toll plazas after those plazas were replaced by the E-ZPass electronic tolling system. Here's the abstract (paragraph breaks mine):

This paper provides evidence of the significant negative health externalities of traffic congestion. We exploit the introduction of electronic toll collection, or E-ZPass, which greatly reduced traffic congestion and emissions from motor vehicles in the vicinity of highway toll plazas.

Specifically, we compare infants born to mothers living near toll plazas to infants born to mothers living near busy roadways but away from toll plazas with the idea that mothers living away from toll plazas did not experience significant reductions in local traffic congestion. We also examine differences in the health of infants born to the same mother, but who differ in terms of whether or not they were “exposed” to E-ZPass.

We find that reductions in traffic congestion generated by E-ZPass reduced the incidence of prematurity and low birth weight among mothers within 2km of a toll plaza by 10.8% and 11.8% respectively. Estimates from mother fixed effects models are very similar. There were no immediate changes in the characteristics of mothers or in housing prices in the vicinity of toll plazas that could explain these changes, and the results are robust to many changes in specification.

The results suggest that traffic congestion is a significant contributor to poor health in affected infants. Estimates of the costs of traffic congestion should account for these important health externalities.

That last line is key. We're used to seeing estimates of the costs of congestion, which tend to peg those costs in the tens of billions of dollars annually in the United States. Those estimates primarily estimate cost in terms of wasted time and wasted fuel. Some may attempt to estimate the cost of additional greenhouse gas emissions. Few take into account the direct health effects of congestion.

It's interesting to think about this research in light of the equity arguments made against congestion pricing. Set aside the fact that drivers tend to be richer than transit riders, and that congestion pricing would generate revenue for progressive transit improvements. Neighborhoods located in the shadows of congested highways are unlikely to be filled with wealthy families.

We want our cities to work better, and congestion pricing is one of the very best policy tools available to help that happen. It can make cities more efficient, more equitable, and greener, and it can lead to improved mobility for transit-riders, pedestrians, cyclists, and drivers.

As tempting as it may be for those who love cities to conclude that whichever policies irk drivers the most are the ones we should adopt, far more progress will be made if we recognize that some of the most promising policy changes can be good for nearly everyone.

Urban areas have a lot to contribute to the congressional climate change debate. (Photo: SDOT Blog)

The takeaway, for me at least, was a clear sense that technology is dramatically changing the lay of the land for local urbanists. Better data (and access to data) are helping to identify potential targets for planning improvements and easier navigation of cities and transit systems. Blogs and social network technologies have allowed urbanists to better communicate with each other, inform the public, and influence local governments.

Rare is the big American city that lacks a vibrant urban blogospheric community.

But there was an odd disconnect at this conference whenever a national policy figure took the podium. Speakers came across as detached and awkward where the web's potential was concerned (Adolfo Carrion) or warm and interested but fundamentally unsure of the best opportunities for engagement (Raphel Bostic).

Whereas New York City Transportation Commissioner Janette Sadik-Khan's talk to the gathering was invigorating because it was clear to all involved how speaker and audience could help each other be effective in achieving common goals, speeches from federal figures landed with the hard thump of uncertainty.

However promising the speakers' expressed goals were, it was less than obvious to all involved how the web might support or influence policy, and how the federal government might deliver tangible results.

I thought of this disconnect as I sat in a meeting on climate policy last night with Oregon Sen. Jeff Merkley (D). In that discussion, it quickly became clear that the messages that are resonating with voters are not related to the economic consequences of warming or the moral case for reducing emissions. The messages carrying the day have very little to do with climate at all.

What works with the American people? A focus on ending dependence on oil and on generating clean energy jobs. Those are the priorities that convince voters to support the passage of a climate bill even after being confronted by an opposition message on the cost, real or exaggerated, of proposed plans.

What these goals translate into, in the mouths of most politicians, and policy wonks, and journalists, is an emphasis on what can be done about the automobile. Merkley, who represents a state containing perhaps the most transit-friendly city in the country and which is home to a company now producing the first American-made streetcars built in decades, didn't mention transit at all until asked about it -- he focused instead on the economic potential in hybrid technologies and electric cars.

Obviously, cars aren't going away any time soon, and it is important and necessary to keep improving the efficiency of the nation's automobile fleet. But this national blind spot where transit is concerned is distressing.

Yes, any climate bill that passes will likely include funding for transit and rail. But given that the biggest selling points of a climate bill are the likelihood that it will reduce American dependence on oil and create green jobs, a major new investment in rail, transit, and cities generally should be given a starring role.

This isn't rocket science. Transit investments are no longer the provenance of the big, old, and dense eastern cities. Metro areas from Norfolk to Charlotte to Houston to Denver are embracing transit. Funds for such investments are oversubscribed.

New money for transit systems could significantly speed the construction of projects currently in the works, thereby pushing forward the time at which development around those systems, perpetually in short supply, can be built. Create more opportunities to build transit-oriented development -- the one kind of housing not oversupplied at the moment -- and you put people back to work.

Additional transit funding allocation could reduce the inclination among city planners to scale back system plans based on current economic conditions. And lest we forget, budget shortfalls amid the recession continue to affect service and threaten transit system jobs. This problem won't go away until something like strong economic growth returns.

Meanwhile, demand for high-speed rail funds is high around the country, and the amounts allocated so far -- while generous relative to what has come before -- are small compared with what it will take to bring functioning systems online. Money for street improvements and new pedestrian and bicycle infrastructure could put people to work almost immediately, in ways that would help reduce transportation costs and emissions.

The obstacle to a greater role for these approaches is largely one of perception. Smart growth and transit are seen as niche solutions -- not something which is likely to be accepted or used by most Americans, who will remain dependent, as ever, on the automobile. But this is where the urban blogging community can be of use.

When you have vibrant communities dedicated to transit investments and better planning in places like Phoenix, Atlanta, and Austin, you have the basis for convincing legislators that these are not fringe policy tools, but rather priorities which should be championed and supported, heavily, at the federal level.

But while urban leaders in cities traditionally wedded to the car are beginning to understand that there is a constituency for a different approach to urban design and transportation, the congressional delegations in those states aren't hearing the message.

To them, the climate bill simply isn't about transportation or urban planning. They're not thinking about improving the bill by increasing the funding for those priorities, and they're not making a decision about whether or not to support the bill on the basis of what they're hearing from local urbanist groups.

I think there has been frustration among urbanists at the way their issues seem to have been sidelined in the Obama administration's first months. With the stimulus law on the books and a federal transportation bill delayed indefinitely, it hasn't been clear to urban advocates how their ideas might be important to the national discussion.

The climate bill is the answer. This is where urbanists can become relevant. The audiences for urban advocacy blogs -- and legislators -- need to hear some important messages. Urban investments can help get us off oil while creating thousands of jobs. A climate bill should make these investments a priority. And passage of the climate bill should be a major priority.

People care about these topics, but for some reason the important connections -- between better urban planning, a greener and more vibrant economy, and climate legislation -- aren't clicking. It's time we made them click.

We investigate the relationship between interstate highways and highway vehicle kilometers traveled (vkt) in us cities. We find that vkt increases proportionately to highways and identify three important sources for this extra vkt: an increase in driving by current residents; an increase in transportation intensive production activity; and an inflow of new residents.

The provision of public transportation has no impact on vkt. We also estimate the aggregate city level demand for vkt and find it to be very elastic. We conclude that an increased provision of roads or public transit is unlikely to relieve congestion and that the current provision of roads exceeds the optimum given the absence of congestion pricing.

The first inclination of most urbanists, when confronted with something like this, is probably to bristle and conclude that the authors are nuts. Transit can't relieve congestion? What would happen to New York or Washington if transit systems were shut down for a day? There would be chaos!

Photo by derang0.

When a transit system is built, two things happen to area roadways. Some subset of drivers will find that commuting by transit is faster, or cheaper, or more convenient (or all three) than driving and will switch to transit. If that were where things ended, then transit construction would indeed reduce congestion.

But there is a knock-on effect. When drivers switch to transit, roads become less congested, and driving therefore becomes more attractive. Drivers who were previously commuting at off-peak times to avoid congestion will switch to peak times, and drivers who were otherwise adapting to congestion by working at home some days or taking longer, alternative routes will adjust their behavior as well.

The end result will be ... a return to road congestion. This may not happen immediately. When new capacity of any sort -- roads or rails -- is built, there may be a time period during which traffic flows more freely, but ultimately settlement and transportation patterns will adjust until roads are again congested.

This happens because roads are under-priced (and often free). If drivers don't have to pay to use scarce road space, and don't have to pay to cover the cost of congestion their driving imposes on others, then drivers will use the road until it is congested. Because the government isn't using price to ration demand (as is done with most consumer goods), demand will rise until the cost of lost time rations demand, and pushes drivers to take other routes or modes.

I don't think there's any point in denying this. Instead, there are key points that urbanists should take to heart.

One is that roads are overbuilt. Years of trying to fight congestion, ineffectually, by building new capacity have generated a road network that is far too large.

Another is that road congestion can only be addressed through imposed rationing, and the most efficient way of doing this rationing is through variable tolling. This, of course, should raise a lot of new and desperately needed revenue.

The third point is that just because transit can't permanently reduce congestion doesn't mean that there aren't good reasons to build transit. Indeed, the authors of the above study conclude that it will often make sense to do so.

What kinds of reasons? Well, just because the road network is overbuilt doesn't mean that all transportation demand is adequately met. In many areas -- particularly in center cities and job concentrations -- new capacity is needed, and transit offers an effective way to move a lot of people through dense areas.

Another reason is that in the busiest areas, congestion tolls are likely to be fairly high, and transit can offer an affordable alternative to driving to low- and middle-income travelers.

And finally, transit can help address one of the key contributors to transportation demand -- poor land use. Transit networks offer a framework around which denser, mixed-use neighborhoods can be built, allowing more people to walk or bike to work or reduce their travel needs. Infrastructure is expensive to build and maintain, and ideally we'd like to grow in a more intensive way that reduces that needed infrastructure for a given amount of land.

Urbanists ought to trumpet these results. Drivers are more likely to accept congestion tolls if it is made clear to them that such tolls are the only way to reduce road congestion. And tolling will create both the demand and the revenue for new transit capacity. The relationship between capacity and congestion is one we'd all do well to understand.

Rosenthal attributes much of this difference to behavioral factors relating, it seems, to Europeans' unique tolerance of inconvenience. She writes:

But even as an American, if you go live in a nice apartment in Rome, as I did a few years back, your carbon footprint effortlessly plummets. It’s not that the Italians care more about the environment; I’d say they don’t. But the normal Italian poshy apartment in Rome doesn’t have a clothes dryer or an air conditioner or microwave or limitless hot water. The heat doesn’t turn on each fall until you’ve spent a couple of chilly weeks living in sweaters. The fridge is tiny. The average car is small. The Fiat 500 gets twice as much gas mileage as any hybrid SUV. And it’s not considered suffering. It’s living the dolce vita.

She later adds:

Also, in Europe, the construction of most cities preceded the invention of cars. The centuries-old streets in London or Barcelona or Rome simply can’t accommodate much traffic — it’s really a pain, but you learn to live with it. In contrast, most American cities, think Atlanta and Dallas, were designed for people with wheels.

What makes this particularly remarkable is that she opens the essay by discussing an experience she has in Stockholm, in which she insists on taking a taxi from the airport, which ends up being much slower and more expensive than the train.

Brad Plumer frames the piece as a fascinating read in light of the "lifestyle taboo," writing:

It's not considered the height of political savvy here in the United States to point out that European lifestyles are greener than our own. Don't expect that line in an Obama speech anytime soon. Too many facets of European life—the cramped apartments, the clotheslines for drying laundry—would likely strike suburbanites as inconvenient, burdensome, or even downright primitive...

Rosenthal wonders whether similar measures could fly in the United States: "I believe most people are pretty adaptable and that some of the necessary shifts in lifestyle are about changing habits, not giving up comfort or convenience." Maybe so, but this sort of talk still tends to be taboo in mainstream U.S. green circles. Josh Patashnik wrote a terrific piece for TNR last year on Arnold Schwarzenegger's brand of "pain-free environmentalism" in California—it's all just peachy to talk about swapping out coal-fired plants for solar-thermal stations, but ixnay on trying to rein in suburban growth or coax people into smaller homes.

I see several problems with Rosenthal's essay and with Brad's framing of it. One is that it's not really correct to attribute the huge gap in per capita emissions between America and Western Europe to the charming European habit of drying their clothes on clotheslines.

As Brad notes, power sources play a major role, whether one is talking about greater use of natural gas, the French nuclear industry, or Iceland's geothermal capacity.

Climate is extremely important. Western Europe is fairly temperate relative to much of America (and especially compared to the dirtiest parts of the country). In the same way, Californians are much greener than Texans, thanks to the moderate conditions along the heavily populated Pacific coast, which reduce the number of days on which home heating or cooling is needed.

But there are lifestyle issues involved, particularly where transportation and land use are concerned. And contrary to Rosenthal, it isn't that Europeans have opted for inconvenience. Rather, they have chosen different conveniences, as her Stockholm air train anecdote makes clear.

It is incorrect to say that an overabundance of land drove America to sprawl, and to drive. The Netherlands is dense of necessity, of course, but in Britain and France and Germany there is ample countryside, which might easily be home to sprawling subdivisions.

But Western Europeans have largely chosen not to encourage such growth, opting instead to tax gas at high rates, invest in transit, and protect center cities from the threat of urban freeways.

I think it is very difficult, objectively, to demonstrate that their choices have produced ways of life that are clearly less convenient than American lives. It is clear that Europeans tend to have better health outcomes than us, and they die in car accidents at much lower rates, and of course they're enjoying levels of wealth similar to our own while producing half as much carbon.

The obvious retort to this line of thinking is that perhaps that's all true, but like it or not America is now sprawling, and any effort to make the country greener by pursuing European land use and transportation options would be very difficult. In a similar vein, it is argued that attempts to push Americans into such a life via gas taxes or carbon prices would wind up being very painful.

But this is not quite right. As I have pointed out before, America will more or less need to build itself all over again by 2050 in order to accommodate population growth. Just because most of America is currently sprawling doesn't mean that most of the America built between now and mid-century has to look the same.

It's also not clear that increasing the push factor on households has to be especially painful. Taxes on drivers can be levied in a progressive fashion, if some revenues are used to fund transit options while others are refunded to lower and middle income households to help offset the added cost of driving.

Congestion tolling would mean higher government revenues and reduced driving, but it would benefit rich and poor alike. As with tax revenues, tolls could be used to provide a cushion against the increased cost for lower income families and increased investment in transit. Higher income households (which will tend to place a greater value on work hours lost to congestion) would enjoy a speedy ride into the office.

If the federal government worked to address limits on urban growth in green cities like New York and San Francisco -- limits which also serve to make housing in such places extremely expensive -- then America could grow denser and greener by improving access for middle-income households to some of the most dynamic metropolitan economies in the country.

Perhaps not all of the policy changes needed to reduce America's carbon footprint will be a walk in the park, but efforts to improve land use and transportation decisions are likely to be some of the most benefit-rich aspects of the climate change fight (as you'd think most people would realize, given the obvious pain of congestion, high gas prices, driving fatalities, and isolation among those unable to drive, among other things).

This storyline -- that changing lifestyles to enhance walkability will be painful -- makes it harder to pass good metropolitan policies and easier for politicans to fall back on the lame argument that Americans simply won't tolerate anything other than the sprawling suburban patterns which have dominated new development in recent decades.

And by reinforcing the idea that some of the most promising and least painful policy changes that can be made are unlikely to "work" here in America, writers and politicians alike ensure that more of the hard job of cutting emissions will fall to the parts of the economy where there are no good alternative options, and where change will be painful for households.

Rosenthal's essay is odd yet revealing. She instinctually attributes European greenness to practices Americans would dub backward, while pretending that the very convenient and green transport options she finds are built, and presumably used, by Europeans based on some peculiarity in their culture that we lack.

But we could build trains! In any given legislative sessions bills are introduced that would move the country toward the level of convenience Rosenthal enjoyed in her train ride to the Stockholm airport. It's just that they don't pass, because "it's not considered the height of political savvy" to embrace those policies, because Americans seem to think that their American-ness will render such conveniences inconvenient.

"Trains won't work here," because "Americans love their cars," and so high quality rail lines aren't built, and so Americans continue to drive. And then we sit around wondering what it is about the European character that makes them enjoy using clotheslines so much.

At the time Sarah Goodyear summarized some of the findings:

The report cites real estate projections showing that two-thirds of development expected to be on the ground in 2050 is not yet built, meaning that the potential for change is profound. The authors calculate that shifting 60 percent of new growth to compact patterns would save 85 million metric tons of CO2 annually by 2030. The savings over that period equate to a 28 percent increase in federal vehicle efficiency standards by 2020 (to 32 mpg), comparable to proposals now being debated in Congress...

Less of this, please... (Photo: SkilliShots/Flickr)

Then about a month ago, the National Academies' Transportation Research Board released its own report on the effects of compact development. In many ways it supported the conclusions of the Growing Cooler report. Increased density can produce significant reductions in VMT. And there's this:

The TRB report suggests that if 75 percent of this new construction is of a more compact variety, that emissions could be reduced 10 percent or more from the baseline scenario (and that is not taking into consideration the deployment of cleaner electricity generation and other potential sources of savings).

Of course, as some commenters noted at the time, the TRB report also quoted figures for a future, a "moderate" scenario, in which a far smaller share of new development was built compactly. On the whole, the authors were a bit more conservative in their view of the effects of increased density, and a good bit more conservative in their assessment of how much density might actually be increased.

The difference in conclusions is largely about the assumptions used to build models. Yesterday, Reid Ewing, Arthur C. Nelson, and Keith Bartholomew offered some comments on the TRB report's findings, focusing on ways in which their assumptions differ.

For instance, with respect to the 75% conclusion quoted above, they write:

Their “moderate” scenario assumes that 25 percent of residential development between now and 2050 will be compact, defined as twice the density of trend development.  Their “upper-bound” scenario assumes that 75 percent of residential development will be compact.  We, on the other hand, assume that between 60 and 90 percent of all new development through 2050 will be compact...

The NRC committee’s “moderate” assumption translates into as much as 80 percent of the built environment continuing to be sprawled, despite the forces described above moving us toward more compact development.  For instance, between 2010 and 2050, more single-person households will be added than households with children. Moreover, roughly two-thirds to three-quarters of the net gain in households between 2010 and 2050 will be among households without children. Housing demand functions of households without children and single-person households are different from households with children.

In other words, much of the growth in low-density suburban development was driven by an increase in the share of households with children (and with multiple children). From the 1970s to the 1990s, the massive baby boom generation was busy having and raising kids, and they overwhelmingly opted to do their child-rearing in suburbs.

But that same generation is now making the transition from suburban parents to empty-nesters to retirees. At the same time, their children are not getting married and having kids at nearly the same rate as they did.

Now, the decline in the share of households with children will eventually be offset by increases in the overall population, and so demand for traditional suburban development will hold steady and eventually increase. But since so much of the current built environment is low density, these demographic shifts mean that most of the new housing built in the coming half century will need to be more compact to satisfy household demand.

That is, household types that tend to prefer more compact development constitute a growing share of a growing population in a world where existing housing supply is not oriented toward such demand. It would be very strange indeed if only 25% of new development were of a more compact sort.

So why did the TRB report conclude, unrealistically, that levels of compact development might be so low? Well, because the process of modeling the future is hard, and scientists tend to be pretty conservative about it. In particular, they're often reluctant or unable to incorporate into their models things that will probably happen, but which are "exogenous" in nature -- that is, outside the scope of the model.

Take the above question. Just how compact new development can be will depend in part on how successful cities are at changing land-use rules that support low-density, car-oriented development. Given increasing demand pressure for more compact housing in walkable areas (and the developer money to be made building it) it stands to reason that local governments will increasingly change their zoning rules to accommodate denser building.

But there is basically no way to incorporate this assumption into a model. It involves the potential for action among thousands of disparate local government organizations, the sitting members of which have yet to be chosen.

A cautious modeler will be reluctant to go out on a limb on this point, and his results will be conservative as a result. That's part of the way reports like this are written, but it doesn't mean that we, as readers, have to dumbly accept that what the report's authors were forced to assume is what the real world will actually be like.

When talking about development forms, there are many such assumptions biasing results toward conservatism.

For instance, it has been very easy in recent decades for developers of suburban tract housing or strip malls to obtain financing for their projects. So common were such development types that Wall Street firms developed standardized financing terms for builders, which served to reduce financing costs.

Denser projects or in-fill projects, by contrast, were less common and more complex. As a result, financing for them required a certain amount of customization. Not only did this frequently increase borrowing costs, it also led many finance firms to abandon the business for less cumbersome opportunities.

Growth in the share of development that is of a compact form will increase the incentive to develop cheaper and more standardized financing options for compact projects, thereby making the construction of additional compact developments easier and more affordable.

But this process is essentially unmodelable. Things will likely work this way, but careful researchers simply can't guess how financial products will evolve in future decades and plug that guess into their models.

The moral of the story is this: whether the topic is the effect of climate change regulations, or high-speed rail system construction, or compact development, experts will produce analyses that try to predict likely outcomes and which will be widely circulated and quoted by policymakers and journalists.

These reports are not the final word. They have to be read critically, with an understanding of the limitations faced by their authors. If you don't get the constraints researchers face, then you can't understand their results.

Tom Friedman (Photo: IvyGate)

According to the energy economist Phil Verleger, a $1 tax on gasoline and diesel fuel would raise about $140 billion a year. If I had that money, I’d devote 45 cents of each dollar to pay down the deficit and satisfy the debt hawks, 45 cents to pay for new health care and 10 cents to cushion the burden of such a tax on the poor and on those who need to drive long distances. 

The first and most obvious thing to point out is that it's far more likely that Tom Friedman's mustache will be elected president than it is that Congress will approve a five-fold increase in the federal gas tax, even one phased in over a decade or more.

There is a reason that gas taxes have not been increased in 15 years: expensive gasoline in America is incredibly politically unpopular, and not without reason. Increases in gasoline prices are painful for American households, precisely because the nation is so dependent on driving.

That's the tricky part. Prices need to be higher to reduce dependence on gasoline, but that very dependence makes price increases political suicide. What is needed is either an extremely gradual increase in gas taxes (on the order of the rate of inflation plus 1 percent per year), or increases in market prices (for which politicians will still be blamed), or an indirect levy of some kind that will act to reduce consumption.

A second point is that a $1 per gallon tax on gasoline and diesel fuel won't raise $140 billion a year for very long. Why? Because consumers respond to price shifts, and they respond a lot to large price shifts.

In 2007, the average, inflation-adjusted price of a barrel of oil was about $67 per barrel, and Americans consumed about 20.7 million barrels of oil per day. In 2008, the price of oil averaged about $91 per barrel (which translates into a gas price increase of about 60 cents per gallon), and consumption fell by more than 1 million barrels per day, to the lowest level since 1998.

The price goes up and consumption goes down, reducing the revenue one earns from the increase in price. What's more, the short-run demand response will often be mild relative to the long-run response.

Faced with an increase in the price of gas, households can't do all that much in the short term to respond. They may cut out unnecessary errands, or carpool, and if they live in an area with good transit access, they'll likely increase transit ridership.

But because of the household location decisions made in recent decades, most households will have few ways to reduce gasoline usage immediately. Consumption will fall, but not by much.

If months pass and the increase persists, then responses will grow more dramatic. Households will trade in gas-guzzlers for more efficient vehicles or buy bicycles. Consumption declines will increase.

And if increases are expected to be permanent, the long-run responses will be significant. Households may begin to choose home or job locations that minimize driving or that allow for use of transit, walking, or biking. Communities may begin designing themselves differently and increasing transit service.

And ultimately, consumption may fall to near zero.

That doesn't mean that driving will fall to zero. Vehicle miles traveled per person will almost certainly decline in such scenarios, but the inevitable switch to electric vehicles or those using alternative fuels will allow millions of Americans to continue getting around by car.

But that won't do a thing for the $140 billion in revenue that Friedman would promise to debt retirement and health care. And whatever portion of transportation budgets is reliant on fuel taxes will be likewise destroyed. So what he might have written is that real men tax gas and then prepare to tax something else.

That something else will probably have to be driving itself, or congestion, or both.

It would be a good idea to charge drivers for their use of the road whether or not there was a gas tax revenue crisis. Congestion costs Americans billions of dollars a year -- a burden on wallets and economic activity that will persist even after the carbon has been wrung out of the transportation sector.

Of course, we run into trouble in assessing congestion fees just as we do with gas taxes. A fee high enough to reduce congestion is one high enough to deter driving -- which is to say, one that is felt and reviled by drivers. That will not be popular.

Even if some share of gas tax revenues is refunded to low and middle income drivers (as it should be), and even if good transit substitutes are built (as they should be), the effect of the increased cost will be to force some behavioral changes -- economically efficient and environmentally beneficial ones, it should be noted, but behavioral changes all the same.

And change is not nearly as welcome as last November's election might have led you to believe (as this summer's political shenanigans should convince you).

And so the best hope for funding is likely a combination of small measures which ramp up over time. Congress, in considering how to fund the next transportation bill, shouldn't be looking for a funding magic bullet; anything that suddenly raises a lot of money will be politically toxic.

A better idea is to focus on small increases in gas taxes along with a rollout of VMT-taxes that begin at low levels -- too low initially to do much about congestion. It will amount to less than anyone in policy-making circles really wants, but it will be a start.

The project represents a unique and ambitious attempt to re-engineer a textbook example of 1960s-era job sprawl. But it has been difficult for many residents of Fairfax, the quintessential suburban county, to accept that the tangled streets of Tysons can be changed into something safe and accommodating of pedestrians.

Regulators, too, are struggling to get behind the shift. Just this week, the Washington Post reported that planners preparing zoning changes for the redevelopment are having second thoughts, and are looking to reduce the allowable density and add new highway interchanges to the plan. Old ways die hard.

George Mason economist Tyler Cowen has long been a skeptic of the project. Apropos of the Post's story, he wrote this week:

It seems the eight “mini-cities” are on the way out.  Why?  The area’s Revolutionary War era roads can’t handle too much additional population density…

That is, in a nutshell, why Fairfax County cannot and will not become like central Arlington in the Ballston and Clarendon areas.  Recall that some time ago Tysons Corner was ranked as #4 in office space in the entire U.S., if it were to be counted as a city.  Many Fairfax County residents look upon Arlington as a quaint experiment, a kind of well-laid out duck pond in somebody’s backyard, but not a model for the broader suburban area.  The walkable part of Arlington is quite small compared to Tysons Corner (by the way I used to live at Tysons and also have spent time walking it) and density in central Arlington doesn’t threaten to crush much of anything…

Rent-seeker he may be, but he’s right to suggest that a much denser Tysons — no matter how well done — will overwhelm the local support roads of Vienna and McLean.  The bottom line is that path dependence is a very strong force in all these comparisons.

This doesn't make much sense. Let’s begin with the obvious — Cowen, a libertarian, seems to approve of the fact that a local planning board will dictate the size of buildings which can be built. What is the justification for this, from his perspective?

Presumably, reducing the opportunity to build in such an economically important area will have significant economic costs, which might well be far greater than the cost of added congestion. Why does Tyler think that the best way to address congestion is through onerous zoning restrictions, rather than, say, tolling or a congestion charge?

There is no attempt here to examine the relative costs and benefits of various options; he just seems to yell “traffic!” and throw up his hands. That’s not a very economic approach.

There are other odd statements in Tyler's analysis. Tysons’ Revolutionary War-era roads inhibit dense building, but Arlington’s and Alexandria’s do not? Tyler is wrong; in terms of land area and employment, Arlington’s walkable areas are quite comparable to Tysons.

And what he doesn’t think to ask is why significant density in Arlington doesn’t threaten to crush much of anything. He seems to assume that it’s either because there aren’t that many people there (wrong), because the area was built to handle vertical density (wrong), or…something else.

There are several important factors. One is that Arlington has a greater residential population than Tysons — more than 200,000 people live in the county, while just 18,000 live in Tysons Corner — much of which lives within easy reach of Metro stations. At present, most Tysons workers live several miles or more away from their jobs and drive to get to them. Perhaps this choice reflects a preference for driving to work, but it’s difficult to know because residential options (and related amenities) are so limited within Tysons.

If lots of housing opportunities are created within walking distance of Tysons jobs, workers will respond to the reduction in commuting costs made possible by such development and will relocate there. Congestion may actually speed this transition, ensuring that residential amenities grow more rapidly within Tysons and reinforcing the transition.

At any rate, a larger residential population within Tysons will mean that a larger share of Tysons workers will walk to work. The presence of Metro will mean that a larger share of commuters will take Metro to work.

And here is one of the most important points of all. At present, most trips within the Tysons area require a person to get in his car and drive. Daytime errands, trips out to lunch, or meetings at buildings across the way mean, by and large, a car trip, because the pedestrian and transit infrastructure is so bad within the area, and because density is reduced as a result.

The big idea of the plan is to fix this. If you work in Clarendon you can walk to get lunch, walk to the nearby copy shop, and Metro to other offices in Ballston, and Rosslyn, and Washington. Not everyone gets around in this way. Many people continue to drive. But by creating the walking and transit options, a large share of the intra-area traffic is removed from roads, clearing the way for inbound and outbound traffic.

I suppose it is open to debate whether these traffic-mitigating effects will offset increased demand for road space generated by the redevelopment, but Tyler seems uninterested in exploring the question. Certainly, the Arlington experiment offers hope for Tysons, even if Fairfax residents foolishly think of it as a duck pond while they cool their heels in traffic. And I’m not really sure what kind of future Tyler sees for Tysons in the absence of this kind of redevelopment.

At any rate, it does seem odd that once again, we have a libertarian-ish figure cheering on the planners’ decision to artificially reduce density.

Do federal gas taxes really charge "users" of the highway? (Photo: CAP)

The Interstate Highway System accomplished all of this [construction of the system] without any subsidies. Federal highway user fees paid for 90 percent of the cost of the system, and state highway user fees covered virtually all of the remaining 10 percent.

This brings up an interesting question: What is a user fee? Common sense would suggest that a user fee is a fee paid by a user of something in order to use that something. A common example might be a train fare. When one wants to ride a train, one purchases a ticket. One doesn't purchase a ticket if one doesn't want to ride the train, and one doesn't ride the train without a ticket. A ticket is specifically meant to extract a fee from a potential user, that that user might then be allowed to use the train.

So do gas taxes count as highway user fees? Well, one might pay gas taxes even if one never uses highways. You pay the gas tax on gas used to drive down local roads or private driveways, or to power lawnmowers and tractors that never even see publicly-funded blacktop.

And one can use highways without ever paying gas taxes. Anyone able to obtain a vehicle powered by natural gas or electric batteries or canola oil can ride on the federal highway system for thousands of miles and never pay one cent to do so.

So gas taxes are not user fees. Indeed, the lack of actual user fees is one reason American highways suffer from severe congestion problems; when you give away something valuable for free -- like scarce highway space -- it ends up seriously over-consumed.

As a thought experiment, let's consider a world in which federal gas taxes functioned more like a user fee. That is, let's imagine that when drivers fill up, they pay a federal gas tax only on the gasoline consumed while driving on federal highways. That's still not really a user fee, but it's a little closer.

Light vehicles traveled a total of around 2.8 trillion miles in 2007, of which about 23 percent were driven on interstate highways, according to the Department of Energy. If we divide the total number of miles driven on interstates by the weighted average fuel economy of cars and light trucks, we find that about 31 billion gallons of gas were consumed on highways in 2007. That's a lot!

Next, we know that the Federal Highway Administration budget is around $39 billion. If we assume that truck and diesel revenues are unchanged, then we have about $24 billion in highway funding to be covered by a tax on those 31 billion gallons of gas, for an estimated gasoline tax of about 80 cents per gallon.

That's an extremely rough estimate. In fact, the nation's light vehicle mileage includes some diesel-burning engines. If we adjusted the calculations to reflect that, the estimated tax rate would be higher. Highway fuel economy is also higher than the average figures, which means that the calculations above probably overstate the gallons of gas burned on highways. This, too, means that the estimated gas tax rate is too low.

An appropriate gas tax rate to cover the annual highway budget -- which many argue is far too small -- would be on the order of about $1 per gallon.

All in all, this should illustrate that if you set aside all the O'Toole hand waving about trust fund revenues shifted to other modes, you still wind up in a world where federal roads come nowhere near paying for themselves.

One final point: We learned last year that it doesn't take much of an increase in the price of gas to generate reductions in VMT and increases in transit use. If we adjusted the current price of a gallon of gas to reflect an appropriate federal gas tax, gas would be selling for nearly $3.50 per gallon, on average.

With gas at that price, travelers would drive less and use transit more often. During the gas price spike last year, we saw a number of transit systems enjoy high demand during peak periods, to the extent that fares might easily have been raised to reduce system overcrowding.

In other words, what transit systems can charge riders depends upon what the government is (or isn't) charging drivers. This is exactly what we'd expect; if Coke began heavily subsidizing its sodas, Pepsi would have to find a way to cut its prices or face going out of business.

What we see then is that there are two funding equilibria. If drivers pay a fair price for the use of roads, then highway revenues rise and transit fares can rise until both modes are full but not congested. This is the high revenue equilibrium.

But if drivers don't have to pay a fair cost for the use of roads, then highway revenues will be low, roads will be congested, and transit systems will have too little ridership, such that transit systems will be unable to raise fares without losing riders to the already congested roads. This is the low revenue equilibrium, and it's a bad place to be -- inefficient use of all modes, costly road congestion, and a constant shortage of funding for needed infrastructure maintenance and investment.

That's where we are now.

When Congress finally gets around to crafting a transportation reauthorization, it would be nice if they recognized some of these dynamics. America needs smarter infrastructure investment rules, but it also needs smarter revenue-raising methods. If you get the money the right way, that makes it easier to spend the money the right way.

Jane Jacobs (center, in light dress) demonstrates at New York City's old Penn Station. (Photo: Metropolis)

These efforts are interesting because they manage to earn a degree of sympathy from urbanists themselves, who have grown increasingly tired of the decades required to navigate a transit line from planning stages to operation.

There is something very attractive about an individual who can drive the stakes and get the project built -- damn the politicians, and damn the NIMBYs.

But this is dangerous territory. In rehabilitating Moses and reconsidering Jacobs, it's important to be clear about where each was right, and where each went wrong.

There are many ways to interpret the clash between Moses and Jacobs: development versus preservation, city versus suburb, design for people versus design for automobiles, power versus powerlessness, and so on. To acknowledge that the balance has swung too far in one direction in one of these conflicts does not at all suggest that the balances are similarly out of whack on others.

Take, for example, one of Glaeser's principal intellectual standbys: that resistance to development slows the growth of housing supply, increasing housing costs. Glaeser says:

Jacobs underestimated the value of new construction—of building up.

The Death and Life of Great American Cities argues that at least one hundred homes per acre are necessary to support exciting stores and restaurants, but that two hundred homes per acre is a “danger mark.” After that point of roughly six-story buildings, Jacobs thought that neighborhoods risked sterile standardization. (The one public housing project that Jacobs blessed, at least initially, had only five stories.) But keeping great cities low means that far too few people can enjoy the benefits of city life. Jacobs herself had the strange idea that preventing new construction would keep cities affordable, but a single course in economics would have taught her the fallacy of that view. If booming demand collides against restricted supply, then prices will rise.

The best way to keep cities affordable is to allow private developers to build up and deliver space. Jacobs was right that high-rise public housing is a problem, as street crime is much more prevalent in high-rise, high-poverty neighborhoods. But in more prosperous, privately managed buildings, height is not a problem. If you love cities, as Jacobs certainly did, then presumably you should want the master builders to make them accessible to more people.

In this, Glaeser has a point. The opportunities to live in walkable, transit-oriented neighborhoods are extremely limited, and so safe, walkable, transit-oriented neighborhoods tend to be quite expensive. When regulations or NIMBYs block new developments, they limit access to this already limited supply, in the process hurting the causes of affordable housing and environmental sustainability.

On the other hand, it's difficult to understand the ferocity of urban anti-development forces without reference to the battles that hardened their views.

In Washington D.C., where I live, urbanists are routinely frustrated by neighborhood groups opposing new infill developments around Metro stations. These individuals are often outraged by the encroachment upon their neighborhoods and reluctant to listen to the arguments in favor of new walkable, transit-oriented developments around what is a very valuable piece of transit infrastructure. This is occasionally maddening.

But these neighborhood groups were often forged in the highway battles of the 1970s, when planners sought to run freeways through Washington neighborhoods to downtown. Where the highway and public housing builders were successful, neighborhoods were irreparably damaged. The stubbornness is a reaction to the insensitivity of earlier cohorts of urban planners. Had Moses and his ilk been less Moses-like, Glaeser would not find himself so frustrated by construction limits today.

It's also worth asking whether Glaeser's ire is best directed at urban neighborhoods, rather than suburban ones. If you love cities, and if you love the things that cities do well, perhaps you should take aim at the heavily regulated, extremely low-rise metropolitan periphery.

Consider this: The Bronx is home to about 1.4 million people who live on 42 square miles -- a remarkably dense area by American standards. Next door in Westchester County, about 950,000 people live on 433 square miles -- dense for America but much less dense than the Bronx.

In 2004, the Bronx permitted the construction of nearly 5,000 new housing units to Westchester's 1,800. The following year, the numbers were again 5,000 for the Bronx, and only 1,300 for Westchester.

Tiny, dense Bronx County seems to be doing a much better job accommodating new housing units, regulations and all. And this is no outlier. Queens packs more people onto less land than neighboring Nassau County, and suffers from New York's burdensome zoning regulations, and yet Queens managed to approve far more housing in recent years than Nassau County.

Glaeser could use some perspective. New York City packs more than 8 million people into 300 square miles, while the New York metropolitan area has 19 million people spread across over 6,000 square miles. If you doubled the density of the metro area outside the city, you'd make room for an additional 11 million people, while still keeping the metro population density below the level of the least dense New York City borough.

In other words, supply restrictions bind most in the suburbs. Were the suburbs developed on the scale Jacobs favored -- think about those five-story buildings -- the New York metro area might easily contain three times the housing units it currently has. That's a lot of downward pressure on prices.

Glaeser also goes astray in confusing the importance of building infrastructure with the importance of building a certain kind of infrastructure. He says:

Jacobs was right that cities are built for people, but they are also built around transportation systems. New York was America’s premier harbor, and the city grew up around the port. The meandering streets of lower Manhattan were laid down in a pedestrian age. Washington Square was urban sprawl in the age of the omnibus. The Upper East Side and Upper West Side were built up in the age of rail, when my great-grandfather would take the long elevated train ride downtown from Washington Heights. It was inevitable that cars would also require urban change. Either older cities would have to adapt, or the population would move entirely to the new car-based cities of the Sunbelt.

When Henry Ford made the car affordable, millions of Americans understandably wanted to drive. After all, the average commute by car in the United States is twenty-four minutes, whereas the average commute by public transit is forty-eight minutes. The automobile certainly created great challenges for every older city that was built at highway-less higher densities. No matter what Jacobs thought, there simply was not a car-less option for New York. For the city to continue growing and changing and leading the world, it needed to be retrofitted for the automobile. And that enormous task was given to Moses. Perhaps he did too much for the car. I am certainly on Jacobs’s side on the Lomex issue, and cannot possibly approve of the destruction of Tremont; but New York’s fall would have been far more precipitous if it had ignored the automobile altogether.

It is hard today to accept the allegation that Moses was responsible for New York’s demise. The troubles that New York experienced in the 1970s were hardly unusual. Except for Los Angeles, every one of the ten largest American cities in 1950 lost at least 10 percent of its population over the next thirty years. New York is exceptional not in its decline but in its resilience, and perhaps Moses deserves some credit for that. New York and Los Angeles are the only two of those ten big mid-century cities that have gained population over the past sixty years.

For a New Yorker, Glaeser has an odd sense of the attractive qualities of his home city. The people aren't there for the highway bridges. New York City in particular -- and Manhattan specifically -- are the least auto-friendly parts of the entire country, Moses or no. And yet, as Glaeser admits, they continue to grow. Maybe Moses saved New York, or maybe he risked its future unnecessarily by threatening to destroy the density that makes it so vibrant.

And meanwhile, we have counterexamples. London opted not to build any motorways through the heart of the city, and yet it has managed to remain one of only a handful of global financial and cultural capitals.

Glaeser fails to entertain the obvious hypothetical: What might have happened to New York if Moses had focused instead on transit and rail construction, rather than accommodation of the automobile?

Robert Moses (Photo: Cup of Cha)

The difficult question, then, is not whether to make some accommodations for the automobile but how to do so. And it's not at all clear that Moses' approach was the right one, or indeed, even a very good one.

We have good evidence that Glaeser, and Moses, are wrong. To cite just one example, a 2006 paper by Nathaniel Baum-Snow reads (emphasis mine):

Between 1950 and 1990, the aggregate population of central cities in the United States declined by 17 percent despite population growth of 72 percent in metropolitan areas as a whole. This paper assesses the extent to which the construction of new limited access highways has contributed to central city population decline. Using planned portions of the interstate highway system as a source of exogenous variation, empirical estimates indicate that one new highway passing through a central city reduces its population by about 18 percent. Estimates imply that aggregate central city population would have grown by about 8 percent had the interstate highway system not been built.

What New Yorkers were after wasn't the car, specifically; it was the promise of mobility offered by the car. But the job of city planners is to understand how to improve mobility across the entire city and region.

Given the density of New York, the space occupied by automobiles and parking structures, and the sheer cost of land in the city, construction of expensive, low capacity roadways seems like a poor decision.

Ed Glaeser is right when he says: "Successful cities need both the human interactions of Jane Jacobs and the enabling infrastructure of Robert Moses." But he seems unable to grasp that successful cities need city-oriented infrastructure, which actively facilitates those human interactions.

Most of the people who work in New York don't get there by driving, on Moses' highways or any other streets. They take transit, and many others can bike or walk thanks to the density that transit facilitates.

Moses didn't just get the means wrong, he also messed up the ends. And if present and future master builders don't learn better than he -- and Glaeser -- how infrastructure serves a city, they'll likely end up as loathed as Moses himself.

(Photo: Penn State)

But there's not as much in the way of hard studies of the effects of land use as we might like -- mainly because it's been a non-issue, so far as most of the country is concerned, for much of recent history.

Aiming to address this (and acting under a congressional mandate), the National Academies' Transportation Research Board recently undertook a study of the issues, which has now resulted in a very large report entitled: "Driving and the Built Environment: The Effects of Compact Development on Motorized Travel, Energy Use, and CO Emissions."

The report is actually five mini-papers, and at nearly 200 pages long it makes for a lot of reading. But the findings reported in the introduction give an idea of what it's all about.

The authors conclude that compact development is likely to reduce VMT: "The effects of compact, mixed-use development on VMT are likely to be enhanced when this strategy is combined with other policy measures that make alternatives to driving relatively more convenient and affordable." No surprises there.

Finding No. 2 is: "The literature suggests that doubling residential density across a metropolitan area might lower household VMT by about 5 to 12 percent, and perhaps by as much as 25 percent, if coupled with higher employment concentrations, significant public transit improvements, mixed uses, and other supportive demand management measures."

They note that were you to move the residents of Atlanta to an area built like Boston, you'd lower the Atlantans' VMT per household by perhaps 25 percent.

Better land use results in reductions in energy use and carbon emissions, the authors report, from both direct and indirect causes. (Direct causes would be a reduction in VMT; indirect include things like longer vehicle lifetimes from reduced use and the greater efficiency of smaller or multi-family housing units.)

But one of the crucial pieces of data included in the report is this:

As many as 57 million new housing units are projected to accommodate population growth and replacement housing needs by 2030, growing to between 62 and 105 million units by 2050 - a substantial net addition to the housing stock of 105.2 million in 2000.

Critics of smart growth efforts or rail and transit investments often wave off the potential gains from building differently by noting that so much of the current housing stock is of the sprawling, single-family home, auto-oriented sort. Convincing the people who currently live in such places to give that up for something different, they say, is sure to be an extremely difficult sell.

But that's not the issue. No one is suggesting we rip down all of suburbia. Rather we, or at least I, am pointing out that between now and mid-century, the country will very nearly have to build itself all over again to accommodate population growth. In addition to the 100 million homes now in America, somewhere between 62 and 105 million more we be built.

The critical question is what the balance of that new construction will look like. The TRB report suggests that if 75 percent of this new construction is of a more compact variety, that emissions could be reduced 10 percent or more from the baseline scenario (and that is not taking into consideration the deployment of cleaner electricity generation and other potential sources of savings).

Ed Glaeser, and this is kind of hard to believe, argued that land use shifts from building high-speed rail between Dallas and Houston would not provide much in the way of benefits, since, he guessed, only 100,000 or so people in each city would move from the suburbs to the central city. But this entirely misses the point.

Houston and Dallas may each double their current housing stock between now and 2050. Where are those homes going to go, with what climate impacts? That's the critical question.

Demographic shifts and changes in energy prices are sure to encourage some households that are currently living at low densities to move to more compact developments, and that's a good thing. But that's not the main reason to begin focusing on the significant available savings from smarter land use decisions.

The main reason is the growth that America will continue to face. It's difficult to imagine that the nation can double its housing stock while building in a sprawling fashion without facing major environmental costs and economic difficulties. Land use patterns will need to change. And as this report documents, there will be considerable advantages to facilitating that change.

(Photo: Newsday)

Was CARS a good policy, all things considered? Let's look at a few of the latest numbers on the program.

There were approximately 1.17 million vehicle sales in August, which works out to a seasonally adjusted annual rate of about 14 million vehicles. June's sales rate was under 10 million and near the recession low, while last August's rate was also about 14 million. Meanwhile, the August norm in good times was about 16 million.

What does that say about the value of the program? Well, let's say that August sales would have matched June's sales in the absence of CARS. They almost certainly would have been higher given economic improvements between June and August, but for argument's sake, let's say they were the same. We can then estimate how many additional sales CARS produced and the actual subsidy per new sale.

Here's economics blogger Calculated Risk:

If Edmunds.com is correct, and total sales were 1.17 million...in August, then the tax credit only generated about 320 thousand extra sales. Of course some regular car buyers might have put off a purchase to avoid the rush in August, so this isn't perfect, but instead of costing taxpayers $4,170 per car (as announced by DOT), the cost to taxpayers per additional car sold was close to $7,200.

In other words, CARS just didn't generate that many new sales. Much of the subsidy went to buyers who would have purchased anyway.

As it turns out, much of the subsidy also went to people who weren't interested in purchasing GM or Chrysler vehicles. While year-over-year sales figures rose in August for Ford, Honda, and Toyota, sales declined by 15 percent and 20 percent respectively for Chrysler and GM. To the extent that CARS was designed to help struggling American automakers, it doesn't seem to have had the desired effect.

Particularly worrisome is today's report that sales fell precipitously in the last week of August -- after the CARS program ended. Rather than generate momentum for the automobile industry, CARS may have primarily moved sales around. To a certain extent, it might also have been counterproductive. How so?

Given fixed supply, a purchase subsidy will often just lead to an increase in price:

Jeremy Anwyl, CEO of the auto Web site Edmunds.com, said dealers and automakers clearly gained from the big boost in sales. But while the incentives helped consumers, average prices for vehicles went up as buyers less concerned about prices rushed to take advantage of the rebates.

Inventory shortages from the popular program could keep prices high and drive down new vehicle sales. "We have created a sales bubble and now that bubble has burst," Anwyl said.

And while Transportation Secretary Ray LaHood claimed that CARS saved jobs and the the inventory draw-down would lead to increased production, automakers are likely to be cautious in building new vehicles if demand appears unsustainable. The White House's claim that CARS will boost third quarter output by 0.3 percent to 0.4 percent will not prove accurate if September sales fall back below trend.

And then there's the environmental effect of the plan. Much attention has been paid to the fact that purchased vehicles were some 9 miles per gallon more efficient than traded-in vehicles. As I've noted before, much of that gain would likely have taken place without the program, based solely on the fact that oil prices rose steadily over the past decade.

One pair of economists estimated that the carbon savings from the CARS program worked out to roughly $596 per vehicle -- well below the voucher values of $3,500 or $4,500 per new vehicle. Another economist estimated that the implied cost of carbon under the program was somewhere between $237 and $500, much higher than what is assumed to be an efficient carbon price.

No matter how you cut it, CARS was an expensive means to reduce emissions.

That doesn't mean that it was a total waste. There was almost certainly some positive economic and environmental impact from the policy.

But that $3 billion could have been used elsewhere. Other potential programs -- restoring heavily used transit services trimmed by budget cuts or funding weatherization programs, for instance -- would almost certainly have been greener and more stimulative.

In the end, "cash for clunkers" should be understood as a missed opportunity, politically attractive but far from ideal as policy.

Now, others have already begun to do this. California has released a lot of documentation and research related to its decision to construct a high-speed rail network. At a more casual level, Chris Bradford and Yonah Freemark have shown that simply by making a few reasonable assumptions, the stripped down models used by Ed Glaeser produce results that are far more favorable to rail investment.

But I think it's worth stepping back and considering the decision to build HSR in context. The biggest problem I have seen with critical arguments is that they ask the wrong question, namely, given current conditions could a single HSR line be profitable.

That's not the way to make these decisions, and indeed, if we had been making decisions like that all along, much of the country's existing infrastructure would never have been built. So let's see if we can't arrive at a better understanding of the question to which some of us believe HSR is the answer.

In this country, we do not build transportation infrastructure for profit. Perhaps this is upsetting to the libertarians among us, but that's how it is and how it should be.

Rather, we build transportation infrastructure because we recognize that mobility is vital for the economic, social, and political life of the country. The question then becomes, what criteria does government use to build new infrastructure? What is government trying to accomplish?

To a significant extent, these decisions are not wisely made. Local governments often plan new roads based on what developers want and what federal funding is available to them.

Planners often make plans that attempt to figure out where growth will be or should be, and their advice is occasionally heeded. Limited cost-benefit analyses and environmental impact statements figure in decisions but are rarely binding.

The point is this -- the decision to build a new highway or a new airport is rarely the result of a rigorous analysis of the totality of costs and benefits, to individuals, taxpayers, and society.

That doesn't mean that we should feel good about building rail whether or not it makes economic sense. It does mean that the existence of highways and non-existence of HSR should not be taken as evidence of any kind of intrinsic economic goodness on the part of highways.

So, having said all of that, let's set out a few key facts for consideration. First, current infrastructure appears to be inadequate. Roadway congestion in America is quite costly. The Texas Transportation Institute has estimated annual congestion costs around $80 billion.

That works out to annual costs of approximately $10 billion for Los Angeles, $8 billion in New York, $3 billion in Atlanta and Dallas, $2 billion in Philadelphia and Boston, and so on down the line.

These numbers are open to dispute; congestion costs are difficult to estimate. But it is clear that significant amounts of valuable time and fuel are wasted everyday due to crowded conditions on highways and city streets.

Congestion is worsening in large metropolitan areas, and serious congestion costs can be found in progressively smaller metropolitan areas. Airline delays have also gotten progressively worse in recent years, particularly in our largest metropolitan areas.

Now, congestion at airports and on roads can be reduced by increasing the cost of using those modes. Congestion declined with increases in the price of oil in 2007 and 2008. Unfortunately, the economy's dependence on oil meant that high oil prices contributed to the onset of a serious recession.

It's also worth noting that increases in the price of oil and decreases in driving and flying took place alongside increases in usage of transit and rail. This reflects that rail is a substitute for highway and air travel, and that increases in the cost of the latter will boost demand for the former.

A third piece of information: the American population is forecast to grow by over 100 million people over the next four decades.

Currently, the Census Bureau projects that the United States will be home to approximately 440 million people in 2050, about 133 million more people than currently reside in the country. Based on recent trends, it seems likely that most of those people will live in the country's metropolitan areas.

Based on these pieces of information, it seems clear that if nothing is done, congestion will continue to increase. Ultimately, this will lead to a steady reduction in mobility within and between the nation's metropolitan areas, with negative consequences for economic activity and social welfare.

The question, then, is this: what should be done about this state of affairs?

One potential answer is what you might call the no-build solution -- no new capacity of any sort will be built. Governments might choose several options within the no build solution; they could truly do nothing, or they could choose to ration demand by pricing roads and airport slots.

In either case, however, the cost of traveling by road or air would rise. This could be reflected as an increase in time cost or monetary cost or both.

However the increase occurs, recent experience suggests that the rising cost of travel by car or plane will lead to an increase in demand for substitutes. In the absence of action, then, demand for transit and rail will be enhanced (and cost-benefit analyses should reflect this).

Note: I'm not mentioning oil prices at all here. It's not easy to predict where prices will go tomorrow to say nothing of four decades down the road.

It does seem likely, however, that oil price volatility may increase in coming years (and has already increased since the placid days of the 1990s). In that case it's worth considering the value of an acceptable substitute to driving and flying. The better consumers can adjust to swings in oil prices, the less economic damage such swings will do.

Now, what if we choose to build new capacity? This, it seems obvious to me, is the most likely policy course. Governments will react to complaints about growing congestion as they always have -- by building more capacity.

The question then becomes what kind of new capacity should be built. Glaeser and others have attempted to show that high-speed rail does not pass a simple cost-benefit test. I'm inclined to disagree with their assessment, but to a certain extent, that question is beside the point.

Government is going to build more capacity. Given that, what is likely to be the best investment, all things considered?

Available alternatives, as it turns out, are not all that attractive. Roads do not appear to pay for themselves any more than railways do. Receipts from the federal gas tax come close to covering federal highway expenditures, but gas is used on highways and non-highways alike, indicating that at the federal level, highways are subsidized.

A more detailed analysis by the Texas Department of Transportation led to the development of the Asset Value Index, which was used to gauge the life-cycle cost of Texas roads, highway and non-highway.

According to the Texas research, none of the state's roads paid for themselves, taking into account all relevant taxes and fees. In some cases, gas tax rates would have to be $2 per gallon or more before a piece of infrastructure would break even. Obviously, a gas tax at that level would correspond to increased usage of substitutes, like rail and transit.

Environmentally speaking, rail infrastructure is a much better option than new road or air infrastructure. Ed Glaeser concluded that there are positive environmental gains from building rail, and he was comparing rail to the no-build alternative.

If one assumes that some kind of new infrastructure will be built, then the case for rail becomes more compelling still. Life-cycle emissions for rail are considerably lower than those for driving options.

They're lower than flying options as well, and rail compares most favorably to life-cycle emissions for small planes, which are most common on the short routes that would be in direct competition with intercity trains.

Glaeser did cite research out of Britain as a reason to be wary of the life-cycle emission benefits of high-speed rail, but even there rail comes out fairly well.

The research, a Booz Allen Hamilton study commissioned by the UK Department for Transportation, shows that on routes where rail currently has a low market share (which describes most of the routes being considered for HSR service in America) rail can produce significant emission savings, even taking construction of HSR systems into account.

What's particularly notable about this is that it compares HSR construction to a no-build option, rather than a world in which air services are expanded to alleviate airport congestion.

Very little of this will satisfy those who want to see how rail can earn a profit before moving forward. That's fine, and as the title indicates, this is just the beginning of the argument for high-speed rail.

But it's important to understand the context in which the rail decision is being made. America will be building new intercity transportation infrastructure in the coming decades, of that we can be sure. In many cases, the most attractive of available investment options will be high-speed rail.

Meanwhile, on the other side of Arlington, Fairfax County was enjoying a stunning period of growth. People were flocking by the hundreds of thousands to Fairfax's sprawling residential subdivisions, and employment centers popped up and grew rapidly around freeway interchanges.

The future looked as though it belonged to Fairfax County, and Arlington's decision to target development around its new Metro stations seemed quixotic and anachronistic.

But now, with the benefit of thirty years of hindsight, Arlington seems to have been extraordinarily foresighted in its decision to grow around Metro. From 2000 to 2008, Arlington's population grew by 10% -- all of it infill development, and a remarkable achievement for an inner suburb.

Even more remarkably, this growth has led to a negligible impact on local traffic. Daniel Malouff, author of the BeyondDC blog, reported yesterday morning on a meeting with Arlington's Department of Transportation, at which officials recounted some numbers that had emerged from research on the effects of county development choices.

Among the remarkable statistics:

1. Auto traffic counts in the Pentagon City area are level today compared with counts from 1975. Despite all the development that has occurred there in that time frame, including construction of one of the region’s largest and busiest shopping malls, there has been no measurable increase in traffic congestion.

2. 1,000 units of urban-format TOD housing generates fewer auto trips per day than a single suburban-format McDonalds or 7-11. You can build 1,000,000 square feet of residential TOD and generate less congestion than 2,000 square feet of auto-oriented retail.

Arlington has very nearly maximized the development potential of available land around Metro stations, but it's looking to create new transit access for its communities by building a streetcar line along one of the county's busier thoroughfares (and running along its busiest bus routes). Already, denser, walkable, and mixed-used developments are replacing older strip malls on the planned line.

And of course, Fairfax County has been busily working to reverse its approach to transit and development, its streets and highways having bogged down under the weight of constant congestion.

Back when Metro was originally built, Fairfax did not attempt to lobby for routing through population centers, opting instead for a cheaper alignment along the median of I-66 (for the Orange Line), and along existing rail right of way (for the Blue Line). Stations were almost exclusively surrounding by parking; riders would nearly all arrive by car.

These decisions have proven difficult to reverse engineer, but Fairfax County has been trying. Along the I-66 corridor, the county is encouraging such transit-oriented development as can be accommodated. In Springfield (on the Blue Line), a large, walkable redevelopment plan has been slowly making its way forward despite the difficult economic situation.

But the biggest shift is occuring elsewhere. Fairfax County and the state of Virginia recently won federal funding for a new extension of the Metrorail system, to be run through the densest portion of the county at Tysons Corner.

The Silver Line will be used as a framework around which to completely remake Tysons into a dense, walkable downtown. The area may ultimately be home to over 100,000 people, and an employment center to rival downtown Washington.

The rest of the country will be watching. Tysons represents one of the most ambitious attempts to reengineer a suburban employment and retail center into a pedestrian friendly mini-city, fit for residents as well as workers.

Of course, the opportunities to make these kinds of changes are extremely limited. Very few heavy rail systems have been built in the past half century. Commuter rail and light rail systems are increasingly common in growing cities, but federal funding has simply not been made available for new lines on the necessary scale, and the federal government has not made transit-oriented development a priority in choosing where and how to allocate transportation dollars.

This is an inexcusable missed opportunity given transit-oriented development's record of accommodating population growth without contributing to new congestion. Hopefully it is one Congress will address when it gets around to crafting a new transportation bill.

Despite Glaeser's acknowledgment that his "back-of-the-envelope calculation" doesn't "[represent] a complete evaluation of any actual proposed route," the posts are sure to be read and regurgitated by rail opponents uninterested in having an actual debate on the merits of high-speed rail investments.

Today, the Washington Post's lame excuse for an economics columnist, Robert Samuelson, used numbers from Glaeser's analysis in writing an extremely regrettable piece arguing that investments in high-speed rail are misguided. But this is no honest entry into the discussion of how best to invest in transportation infrastructure. It's a hack job, plain and simple.

Samuelson begins by complaining about Amtrak subsidies, but he can't be bothered to address what those subsidies actually suggest about the competitiveness of fast, intercity rail. On the corridor where service most closely resembles true high-speed service, Amtrak runs an operating profit.

It gets much worse from there. Samuelson argues against rail on the basis of population density, writing:

What works in Europe and Asia won't in the United States. Even abroad, passenger trains are subsidized. But the subsidies are more justifiable because geography and energy policies differ.

Densities are much higher, and high densities favor rail with direct connections between heavily populated city centers and business districts. In Japan, density is 880 people per square mile; it's 653 in Britain, 611 in Germany and 259 in France. By contrast, plentiful land in the United States has led to suburbanized homes, offices and factories. Density is 86 people per square mile. Trains can't pick up most people where they live and work and take them to where they want to go. Cars can.

This is embarrassingly bad analysis. America's overall population density includes vast expanses of land in the west where few people live and where high-speed trains won't be built (have a look at the administration's map of proposed routes here and note how many low-density states are not expected to get service).

The proper point of comparison is the population densities of metropolitan corridors where lines will be built. A child could understand the point, and yet Samuelson, out of ignorance or deliberate obtuseness, doesn't get it.

He follows that up with a similar error:

Distances also matter. America is big; trips are longer. Beyond 400 to 500 miles, fast trains can't compete with planes.

Again, this is just embarrassing. Distances between major cities on planned corridors will be at most 400 miles. No one is suggesting that rail compete with planes on coast-to-coast routes.

This is a hugely important factual point, and Samuelson seems to be entirely ignorant of it. He simply knows nothing about the policies being considered.

Samuelson goes on to make other mistakes; like Glaeser he fails to consider the costs and benefits of alternatives to high-speed rail -- given current congestion levels and expected population growth, new infrastructure of some kind will be necessary to keep the national economy functioning. But given the basic errors mentioned above, it's hardly worth engaging with the piece.

The Post should be ashamed of its decision to publish this. And Glaeser should be at least a little bit uncomfortable that his work is being cited in factually challenged columns by writers who clearly have no interest in honest participation in the discussion.

(Image: Treehugger.com)

Glaeser has quite nearly admitted as much, arguing that he chose the hypothetical Dallas-Houston route -- which is not in the administration's plan for a high-speed network -- in order "to avoid giving the impression that this back-of-the-envelope calculation represents a complete evaluation of any actual proposed route."

But it doesn't take a close read to see that Glaeser wishes to demonstrate that rail investments do not make economic sense. He has not been particularly charitable in acknowledging the shortcomings of his work, and he has therefore left his readers with a very misleading picture of the probable outcome of construction of a high-speed rail system.

I have continued to hold out hope that he'll improve his analysis along the way, but as of today we have the final chapter -- on high-speed rail's potential reshaping of the American economy -- and it, too, is embarrassingly bad.

In his earlier posts, Glaeser did not take population growth into account -- a rather large failing while analyzing a piece of infrastructure we can expect to last for decades. This time around he aims to defuse this criticism by writing:

These numbers suggest that costs will exceed benefits each year by $524 million if the rail line has 1.5 million customers, and by $401 million if the region’s rail demand has a huge rate of growth and attracts three million riders.

It's worth recalling where those numbers come from. To arrive at 1.5 million, Glaeser took the current population of the Dallas and Houston metro areas and generated a ridership estimate using the population-to-ridership ratio for the Northeastern Corridor and then dividing by two (to take into account the lower density of the Texas cities).

Looking at the numbers that way, it becomes clear that you don't need anything crazy to happen to get to three million riders. Take expected population growth and partial convergence toward rates of transit ridership seen in the Northeast (or in California, for that matter) and you get there in no time.

Why might rates of transit ridership increase? Both Dallas and Houston are rapidly adding to their transit networks. One might also take into account demographic changes and expected changes in energy and congestion costs, but Glaeser pretends these matters are of no importance and doesn't bother to explain why he has opted to omit them from his analysis.

And as I mentioned before, Glaeser does a poor job estimating direct benefits to rail riders. Using a standard business airline fare and the time saved by flying rather than driving, one gets a more accurate picture of the value of a likely rider's time. Using that more accurate figure, rail's benefits roughly equal its costs even if one accepts Glaeser's 1.5 million rider estimate.

Continuing, Glaeser says high-speed rail investments probably won't make for good stimulus, given that construction wouldn't take place quickly. As I've pointed out before, that's all well and good if you believe that the American economy will be at full employment within a year or so. If you think, as Fed economists do, that full employment may not return for a decade or more, then the stimulus argument in favor of rail grows quite a bit stronger.

What about the potential for high-speed rail to revitalize struggling regions? Glaeser notes that there are good historical examples of infrastructure investment boosting regional economic fortunes, but, he says, these may not apply to the case of high-speed rail. Why not?

Well, because Buffalo is too far from New York to bring any significant competitive advantage over flying. And Philadelphia should be a beneficiary of the Acela, he says, but falling population in that city suggests that it isn't.

There are many things wrong with this argumentation. One is that Glaeser's own method for comparing rail versus flight times shows that rail from Buffalo to New York City still produces a nice time advantage. Take a 90 minute flight time, add the hour early one has to arrive at the airport and 36 minutes of travel time to and from airports, and you get a little over three hours for flying to two and a half for the train. That's not nothing.

Glaeser also waves off the utility of a Toronto to Buffalo line based on the inconvenience of crossing the border, but flyers and drivers must also deal with a border delay, so it's not clear why that's a big deal.

Meanwhile, the blithe use of population change in Philadelphia as a proxy for economic benefit is a little silly. For one thing, it would seem to ignore actual trends. Since 2000, the rate of population decline in the city of Philadelphia has sharply diminished.

From 2000 to 2001, the city's population declined by 15,000. From 2003 to 2004, by contrast, population fell by just over 7,000. And from 2007 to 2008, Philadelphia lost a mere 1,200 people.

Just using Glaeser's fly-by-night statistical methods, it seems as though the introduction of the Acela has in fact materially slowed population decline in Philadelphia. And obviously there are other variables which show that Philadelphia has enjoyed a serious economic rebound over the last decade.

A bigger failure is that Glaeser doesn't consider the value of bringing Buffalo closer together with other Midwestern metropolitan areas. The value of economic interactions between metropolitan economies is a function of the size of the urban economies and the distance between them.

Lowering the time and cost of intercity travel between struggling Midwestern cities should effectively allow those places to lever up the size of their metropolitan economies. Intercity commerce should increase, leading to improved economic conditions.

Glaeser next turns to whether rail investment might change land-use patterns within cities. He says that there is unlikely to be much in the way of a shift from suburb to city, citing this paper by Nathaniel Baum-Snow and Matthew Kahn.

They find that transit use declined from 1970 to 2000, largely due to suburbanization. Millions of people moved from places where there was transit to places where there wasn't transit, and so transit's share of trips declined.

What does this tell us about transit's ability to guide land use? I suppose it says that the presence of transit can't reverse a wave of depopulation driven forward by failing city finances, desegregation, urban riots, and so on. I suppose it says that if people are moving to suburbs and suburbs are overwhelmingly served by road infrastructure, then transit's mode share will fall.

But what it also suggests is that land use isn't simply an endogenous factor responding to changes in household tastes and wealth. Rather, it's a function of deliberate government policy.

If one builds a transit system and surrounds the stations with parking, then no, transit will not do very much to shift land uses. If one builds a rail line between cities that do not allow dense, mixed-use development patterns, well then those patterns won't emerge, it's safe to say.

So an important question to ask is how land use patterns have shifted after construction of rail or transit, in places where governments have facilitated a shift. And I think there can be little question that the answer to such a question is very different than the one arrived at by Mr Baum-Snow and Mr Kahn.

This is also a message that has resonated with many city governments in recent years. Increasingly, changes in land-use are being specifically targeted as a potential benefit from new infrastructure construction. Governments are learning. Economists may not be.

At any rate, Glaeser reveals the extent of his short-sightedness by concluding (charitably, in his view) that rail might lead 100,000 suburbanites to move to the city in both Dallas and Houston, generating some $30 million in gains.

But this is all wrong. The question is not whether high-speed rail will lead some number of suburban residents to pick up and move to the city (although demographic shifts suggest that is likely to happen).

Dallas and Houston will each add a million or more people in the next two decades. America will probably grow by 130 million people between now and 2050. These people will, in all likelihood, live somewhere.

Where they live will be a function of the infrastructure that we build. I suspect that even Glaeser will agree that had the United States developed the Eisenhower high-speed rail network rather than the Eisenhower interstate highway system, our urban geography would be significantly different today.

If we build no new transportation capacity, then existing infrastructure will rapidly become choked, adding to the potential benefits to be had from building rail.

If we instead build new highway and airport capacity, then that will influence future development patterns and mode share. I challenge Glaeser to demonstrate that that future is greener and better off economically than one in which rail is built.

This is the principle shortcoming of Glaeser's analysis -- that it fails to take into consideration the alternatives.

I believe that increasing metropolitan congestion, rising energy costs, changing demographics, and new transit investments will generate a shift in housing and transportation preferences in coming decades. I think it's wise to accommodate this shift by building high-speed rail.

Glaeser seems to believe that in coming decades congestion costs will cease rising; otherwise he'd build future increases into his model. He seems to think that the addition of over 100 million new Americans need not lead to any new infrastructure investment; otherwise he'd compare the economic benefits and life-cycle emissions of rail investments to alternative investment plans.

I think those beliefs are daft and indefensible. And four posts into his high-speed rail series, Glaeser hasn't given any of us reason to think that his analysis is worth taking seriously.

Eric Morris of UCLA's Institute of Transportation Studies (Photo: ericandrewmorris.com)

Let me just begin by pointing out how utterly ridiculous this comparison is. The Obama administration's vision for high-speed rail essentially involves a multi-decade effort to significantly upgrade transportation infrastructure along several of the country's most economically important metropolitan corridors.

"Cash for clunkers," on the other hand, is a $3 billion, roughly two-month program of automobile purchase incentives.

Given this, it's hard to know what Morris is aiming to prove. That "cash for clunkers" makes for a better short-term stimulus? Okay, I'll accept that; high-speed rail is not going to provide much of an economic boost over the next 18 months.

On the other hand, the Kansas City Fed is warning that unemployment might not get below 6 percent again until 2018. If we're looking at a decade's worth of slack in the labor force, which is likely to be a better salve -- a major infrastructure investment program, or ten years' worth of "cash for clunkers"?

Over a longer time frame, the comparison between the policies ceases to be of much use. They're not remotely designed to do the same things. So instead, let's just talk about what each means for the environment.

On high-speed rail, Morris primarily refers to Glaeser's earlier post. That post shows emission savings from rail, despite Glaeser's improperly conservative analysis.

Morris then links to an earlier post of his, which he believes shows that rail isn't green if construction costs are taken into account. But that conclusion only makes sense if you assume that where future infrastructure investment is concerned, it's rail or nothing.

That doesn't describe reality, however. If rail lines aren't built, then some form of new capacity will be constructed to address rapid growth in congestion costs. And if you compare life-cycle emissions for rail to those for automobiles and planes, rail is far greener. I suggest Morris have a look at this paper and focus very intently on Figure 1.

Meanwhile, if we're thinking about life-cycle emissions, let's weigh the impact of replacing perfectly good used automobiles with brand new ones, fresh off the assembly lines -- fuel efficiencies aside.

Morris wraps up these arguments with this stunning phrase:

Because of ... the considerable amount of time the HSR program will need to gear up, HSR’s greenhouse savings will not be felt for years or, perhaps, decades.

I'm led by this to believe that Morris does not actually understand how global warming works -- that it is due to the slow accumulation of greenhouse gases in the atmosphere over time. The only way we'll ever feel any greenhouse savings from any policy is over a considerable amount of time, which is why wonks discuss carbon reductions in terms of what we might be able to accomplish by 2020 or 2050.

Does Morris think that next year will be cooler thanks to "cash for clunkers"? I certainly hope not.

He then goes on to sing the car program's praises. I have previously commented on this, and I'll summarize the view a sensible person should take toward the program.

It is very difficult to know what gains can be attributable to the incentives, as some boost in sales and efficiencies would have happened in any case.

Morris boasts that the mileage of new cars purchased under the plan is significantly better than that for the vehicles being traded in. But that would almost certainly be true in the absence of the program!

Most of the vehicles being traded in were purchased at a time when the real oil price was anywhere from one-half to one-quarter of its current level. And new purchases are likely being made with last year's oil price spike firmly in mind. With or without "cash for clunkers," there would be a mileage improvement, simply based on the reaction to changes in the market price of fuel.

And a rigorous analysis of the program suggests that the emissions reductions from "cash for clunkers" are not at all cheap. A recent paper from the University of California - Davis pegged the implied carbon cost of the policy, in a best-case scenario, at $237 per ton of carbon, with $365 per ton a more reasonable figure.

Morris trumpets the fact that cash for clunkers will pay for itself, noting: "The average customer will reap an estimated $700 to $1,000 dollars per year in reduced fuel costs." But again, this suggests that the program was hardly necessary, since consumers stood to gain from improving efficiency in any case.

Or consider other alternatives. An increase in the gas tax would have immediately paid for itself, being a revenue-raising measure. It also would have encouraged households to increase efficiencies wherever possible, including through the purchase of highly efficient used cars, or through a switch to transit, cycling, or walking -- much cheaper and greener options over the long term.

That would be a hard sell politically, of course ... but that's because it doesn't amount to a massive giveaway to automakers.

Morris then seeks to compare "cash for clunkers" favorably to rail by referencing Amtrak:

Capital costs per rider are dauntingly high: see Glaeser’s post on the direct benefits and costs of HSR here. The system may not even reap an operating profit: Amtrak requires a subsidy of $2.6 billion/year.

I have already addressed Glaeser's faulty numbers here. I'll add that on the one corridor Amtrak runs that resembles true high-speed rail -- the Northeastern Corridor between Boston and Washington -- Amtrak runs an operating profit.

There is a sense in which my criticisms are unfair. These are blog posts, after all. No sensible person would pretend that complex infrastructure investment decisions, which must take into account changes in many different variables over the course of decades, can be adequately analyzed in the space of a blog post or two, or four.

And I would gladly extend to Morris and Glaeser the benefit of the doubt if they were at all careful to point out that their analyses are too simplistic to offer much beyond a list of questions that should be asked of any future, comprehensive analysis.

But they're not. This exercise is, as best I can tell, an effort to show that investments in high-speed rail are not worthwhile, from an economic or environmental standpoint, based on extremely pared down models and faulty assumptions, with the goal of influencing how their readers view the high-speed rail initiative.

It's simply irresponsible. Times readers deserve to be better informed.