Racial Diversity and Exclusionary Zoning: Evidence from the Great Migration

Why do cities adopt and maintain laws that restrict the construction of multifamily housing? Dominant explanations emphasize the economic incentives of homeowners to preserve property values, but this motivation may be underpinned by a preference for racial segregation by white residents. Using new administrative data on zoning, I show that the median central city in the non-Southern United States allows multifamily housing to be built on only 13% of residential land. Leveraging exogeneity in Black migration to Northern cities from 1940 to 1970, I show that increasing racial diversity causes cities to zone less land for multifamily housing. Analysis of public opinion surveys shows urban white voters in areas impacted by migration experienced desegregation and were more racially conservative on housing policy. This suggests that exclusionary zoning was adopted to maintain racial segregation and illustrates how racial threat can embed itself in public policy.