Editors' Summary

The second volume of the Brookings-Wharton Papers on Urban Affairs contains papers and formal discussant remarks from a conference held at Brookings on October 26 and 27, 2000. The symposium for this issue focuses on urban sprawl and decentralization and contains three papers. Edward Glaeser and Matthew Kahn document the enormous decentralization in employment and population that has occurred over the past fifty years and seek to explain these changes. Jan Brueckner sets out a theoretical framework for assessing the claim that the growth of urban areas has been excessive and analyzes several policy options. Steven Raphael and Michael Stoll examine how ownership or access to a car affects employment prospects of minorities in decentralized urban areas. The symposium papers show that although numerous key issues remain unresolved, economists have both the tools and the data to provide important new analyses of what promises to be an increasingly contentious set of issues in the public policy arena.

The other papers in the volume examine current topics of importance to urban economies. Jens Ludwig, Helen F. Ladd, and Greg J. Duncan test for effects of the Moving to Opportunity program on children's educational outcomes. Janet Currie and Jeffrey Grogger explore the determinants of the recent substantial decline in participation in the Food Stamp Program, with a focus on the extent to which changes have been concentrated in urban areas. Dan Black, Douglas Holtz-Eakin, and Stuart Rosenthal examine why minority self-employment rates differ so dramatically across urban areas. These papers are indicative of the broad range of interesting research topics that fall under the "urban" rubric.

Symposium on Decentralization and Urban Sprawl

The enormous decentralization of economic activity has been the central feature of metropolitan development over the past fifty years. Some observers view this trend with alarm and argue that decentralization has led to a series of maladies in central cities as well as to urban sprawl and related problems in the suburbs. Others view decentralization as a positive development, reflecting the preferences of Americans regarding residence, employment, and other factors. A full assessment of decentralization, however, requires facts documenting the extent and nature of the trend, analyses of the causes and consequences of decentralization, and a conceptual framework that integrates these factors. Accordingly, this volume begins with three papers that explore these issues.

Decentralization: Basic Facts and Their Implications

In the traditional view, urban areas have a dense central business district with concentrated employment and production, in order to reduce costs of transportation and information sharing. In such monocentric urban areas, land has the highest value in the city center, where employment density is highest. As distance from the city center increases, land and housing prices fall, lot sizes rise, workers' commute times rise, and the incidence of poverty falls.

This standard view has been increasingly challenged by the trend toward decentralization. Edward L. Glaeser and Matthew E. Kahn document in new ways basic facts of decentralization and analyze the implications for the economic structure of urban areas. They show that in 1940 only one of the ten largest cities had population density below 10,000 people per square mile. By 1990 seven of the ten largest cities had densities below 7,500. Although there is no formal definition of decentralization, urban areas today are highly decentralized: as of 1996, across all metropolitan areas in the United States, only 24 percent of jobs were within three miles of a city center.

Despite the ubiquity of decentralization, there are substantial differences across urban areas. In New York, one of the few cities with concentrated employment patterns, over 45 percent of jobs are within three miles of the city center. In Los Angeles, which is known for its sprawling nature, 45 percent of employment is located within an eleven-mile ring of the city center. The authors also find that the dispersion of employment and population in Chicago, and in most other American metropolitan areas, bears a much stronger resemblance to the spatial patterns in Los Angeles...