Each new radial highway serving large U.S. metropolitan areas decentralized 14% to 16% of central city working residents and 4% to 6% of jobs in the 1960–2000 period. Model calibrations yield implied elasticities of central city total factor productivity to central city employment relative to suburban employment of 0.04 to 0.09, meaning a large fraction of agglomeration economies operates at submetropolitan-area spatial scales. Each additional highway causes central city income net of commuting costs to increase by up to 2.4% and housing cost to decline by up to 1.3%. Factor reallocation toward land in housing production generates the plurality of the population decentralization caused by new highways.

Changes in Transportation Infrastructure and Commuting Patterns in US Metropolitan Areas, 1960-2000 by Nathaniel Baum-Snow. Published in volume 100, issue 2, pages 378-82 of American Economic Review, May 2010

Between 1979 and 2007 a strong positive monotonic relationship between wage inequality and city size has developed. This paper investigates the links between this emergent city size inequality premium and the contemporaneous nationwide increase in wage inequality. After controlling for the skill composition of the workforce across cities of different sizes, we show that at least 23 percent of the overall increase in the variance of log hourly wages in the United States from 1979 to 2007 is explained by the more rapid growth in the variance of log wages in larger locations relative to smaller locations. This influence occurred throughout the wage distribution and was most prevalent during the 1990s. More rapid growth in within skill group inequality in larger cities has been by far the most important force driving these city size specific patterns in the data. Differences in the industrial composition of cities of different sizes explain up to one-third of this city size effect. These results suggest an important role for agglomeration economies in generating changes in the wage structure during the study period.

We perform a comprehensive neighborhood-level analysis of housing supply. Predictions of floor space and housing unit supply elasticities using our estimates average 0.5 and 0.3 across all urban neighborhoods in the United States, exhibiting greater variation within than between metro regions. New construction accounts for about 50% of unit supply responses, with important additional roles for teardowns and renovations. Supply responses grow with central business district distance mostly from the increasing availability of undeveloped land, flatter land, and less regulation. Identification comes from variation in labor demand shocks to commuting destinations, as aggregated using insights from a quantitative spatial equilibrium model.

This paper examines the residential location and school choice responses to the desegregation of large urban public school districts. We decompose the well documented decline in white public enrollment following desegregation into migration to suburban districts and increased private school enrollment, and find that migration was the more prevalent response. Desegregation caused black public enrollment to increase significantly outside of the South, mostly by slowing decentralization of black households to the suburbs, and large black private school enrollment declines in southern districts. Central district school desegregation generated only a small portion of overall urban population decentralization between 1960 and 1990.

Using Canadian administrative data, this paper presents evidence of revenue and productivity spillovers across firms at fine spatial scales. Accounting for the endogenous sorting of firms across space, we estimate an average elasticity of firm revenue and productivity with respect to the average quality of other firms within 75 meters of 0.024. We find scant evidence that the average firm benefits from being surrounded by a greater amount of economic activity at this spatial scale. Sorting of higher-quality firms into more productive locations and higher average and aggregate quality peer groups is salient in the data. (JEL D22, D24, G32, L25, R11, R32)