Thursday, February 23, 2006

Blog Review: Jonathan Levine's "Zoned Out," RFF, 2005.

This scrappy, thoughtful book makes the provocative claim that the causes and consequences of sprawl are less about the excesses of private markets than the excesses of planning.

More to the point, Levine says that unrestrained zoning in favor of modern single-family, suburban housing has so distorted land market decisions that much of the research on the effects of compact development on livability and travel misses the forest for the trees. "But improved understandings of the relationship between land use and travel behavior will not resolve the controversy because travel behavior studies are not designed to shed light on the more fundamental question of why there is so little alternative development to begin with." (p. 23/24).

An example
Suppose Marlon and I study the purported transportation benefits of a feature of the new urbanism, conclude that earlier studies making such claims are deeply flawed, in turn find those benefits are either difficult to verify, case-specific, or potential problems -- and in the end thus question this feature's utility as a dependable source of traffic relief. The problem with this approach, in Levine's view, is that our conclusion is implicitly with respect to an unreliable benchmark -- the status quo -- which itself is overregulated and thus a useless metric.

The good
You have to like the ethos of the story so far. It's consistent with two established policy reform literatures: (1) the theory of the second best, which demonstrates that preexisting distortions change the rules for correcting market failures, and (2) its counterpart in theories of public sector failure, as in Wolf's classic, Markets or Governments (though neither are cited that I noticed). The basic logic is sound. In Levine's terms, what is the default: The status quo, or a less regulated landscape in which developers are more free to test the market for compact developments? (Plus, I can't help but notice the back cover has highly laudatory blurbs from Wachs, Orfield, Calthorpe, Fischel and Downs. One of these guys could be wrong about something, maybe, but not any two.)

Levine's core argument is that compact development is undersupplied. But evidence that this amounts to a problem is not featured until late in the book. (Several early chapters do demonstrate that local land authorities often vex developers and otherwise reduce densities from market levels, and that exclusionary zoning is ... exclusionary.) One example is work indicating that compact developments command a market premium (e.g., Song and Knaap, in the most downloaded Journal of Urban Economics article of 2003).

The book finally presents supportive evidence of its own in chapter 8. That carefully compares the residents of Boston and Atlanta, where the former enjoy more diverse neighborhood/travel environments and thus presumably are less constrained in their travel decisions. Controlling for the mix of preferences, the results indicate that Bostonians are indeed better able to match their housing/neighborhood/travel preferences to their housing choices. Atlantians, with fewer options, would benefit from having more.

We are thus left to conclude that because of credible evidence that many residents of Atlanta would like more compact neighborhoods, that (a) they should be widely permitted (not provided) on that basis and that (b) studies of the transportation effects of neighborhood design are missing the point. Wait, where did that last one come from again?

Random quibbles

  1. The theory of the second best doesn't say that you need to correct the preexisting distortion before addressing new ones, though that is preferred, only that you must account for it. Levine's story does not appear sufficiently nuanced to recognize this, which gives his blanket dismissal of analyses of the transportation effects of urban design the appearance of overstatement.
  2. The book's discussion of "self-selection" bias seems off. Levine is right that we often try to separate out sorting when attempting to measure the pure effect of a treatment, such as the siting of a transit station. (To measure the effect of a new station on the ridership of the average neighborhood resident, we want to control for those who moved there because they are more inclined than the average person to take trains.) He claims, however, that the self-selection of transit users to move near the station is in fact evidence of the treatment in some cases, not a bias to be eliminated. Yes and no. We still need to separate out this sorting in order to measure the treatment effect on the average resident.
  3. As much as I thought I learned from this book, I can't keep myself from believing that when a developer makes traffic improvement claims for their subdivision plan, and those claims -- whether based on wishful thinking, a sincere faith in the general applicability of the simulation results of Walter Kulash, or marketing savvy -- are shown to be false or simply cannot be verified, that this should raise questions about whether the project will make traffic better or worse. Even if I accept that higher densities and more walkable neighborhoods would lessen the frustration of numerous Atlanta residents, and a good many others besides, I don't follow the implication that the possibility of some development patterns worsening traffic is neither here nor there. Apparently I will have to reread Zoned Out.

1 comment:

Kenneth J. Dueker, Portland State said...

Zoned Out, Jonathan Levine, Resources for the Future Press

Reviewed by Kenneth J. Dueker, Emeritus Professor of Urban Studies and Planning, Portland State University


Jonathan Levine has written a thoughtful and provocative critique of zoning practice in the U.S as it relates to transportation and land use. It is an important assessment of the role of zoning in shaping urban areas, particularly the exclusionary nature of some zoning practices that perpetuates urban sprawl and inhibits compact developments. The following section summarizes Levine’s position, while the final section critiques it.

Levine’s Perspective

Levine argues that the tendency of unchecked municipal regulation to exclude density, results in the exclusion of new forms of more acceptable density of the form of compact, walkable, and transit-friendly development. Further, Levine laments the inclination of American scholarship and public debate to identify these regulatory actions as the base case, which is not a market-derived base, thus it distorts the policy debate. He argues that this distorts the transportation and land use policy debate by implicitly treating the status quo as a neutral default choice from which deviations require justifications in travel savings. This results in urban sprawl and paucity of alternative development forms that are the result of governmental regulation, not a free market base case, from which policy reform should be measured.

Instead, Levine argues that interventions on behalf of compact development are worth considering as a remedy for the market failure of exclusionary zoning, and that intervention need not be constrained by proving travel behavior benefits. Increasing the availability of walkable alternatives represents a transportation benefit as surely as reducing traffic congestion and vehicle-miles of travel (VMT).

Levine acknowledges that realizing the benefits of compact development are a long term proposition, and that there might not be a market for compact development in the short term. Nevertheless, he argues that areas around transit stations designated for compact development should not be preempted by low density development

The shortage of affordable housing near ones work and non-work destinations is a result of exclusionary zoning practices of municipalities that favor suburban single-family housing, which is the basis for policy reform to foster more compact development and increased density. He goes on to call for the planning profession to educate local citizens and decision-makers to the importance of accommodating a broader range of housing neighborhood types –not because of proven benefits of compact development forms but because they provide amenable environments for a broad range of housing types, foster walkable neighborhoods, promote vibrant downtowns. In addition, incentive-based policies can help municipalities toward reduced regulatory exclusion, in the form of transit service improvements and incentives to build housing near transit stops. Stronger than incentives, are systems in which land use authority is shared between local governments and regional or state government to overcome local resistance to compact development. For example, statewide growth management mandates hold some potential for overcoming local governmental regulatory obstacles to compact growth. Another example of shared powers is mandating that local zoning conform to a comprehensive plan that is consistent with statewide planning goals.


Levine’s perspective is shaped by observing zoning practice in urban areas that have been shaped by a locally-controlled planning and zoning regime. However, instead of calling for a repeal of zoning he calls for a shared-powers regime to reform zoning. My criticism of his book is one of omission, that it does not proceed to assess and critique early experience and outcomes of application of the shared powers approach he recommends.

He cites the statewide planning program in Oregon as a positive example of the use of incentives and shared powers to foster compact development. In many instances the pace of transit-oriented development in the Portland metropolitan area has lagged in spite of incentives and subsidies. Proponents of compact development justify subsidy based on assumed density and travel behavior benefits. But they have no convincing proof. Levine did not address this situation of whether there is a burden of proof to justify subsidy to compact development. Although he dismisses the burden of proof as a condition to allow compact development, I do not think he should dismiss the burden of proof of benefits when subsidy is involved. Use of subsidy warrants proof of benefits.

Similarly, Levine should examine experience in the State of Washington where shared powers under the Growth Management Act results in mandates to local governments of population growth targets and growth boundaries that beget minimum density requirements. Tightly drawn growth boundaries and minimum density requirements at the urban fringe results in a shortage of low-density development options that is causing gentrification in inner city areas and is displacing residents from what was affordable housing. The lack of affordable housing in the inner city and high land prices at the urban fringe due to a constrained land supply is driving moderate income groups to nearby small towns and rural area, causing longer commutes. Also, this movement to outlying areas might be accelerated if compact development is not well received by housing consumers and they opt to escape from over prescribing it.

The experience in Oregon and Washington, states with statewide planning, raises questions about reforming planning and zoning by the use of shared powers incentives and mandates. Interventions to reform planning and zoning also have unintended consequences. In addition, density incentives and mandates may also negatively impact the quality of development in the absence of good architecture and urban design.


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