Density Zoning Interacts With Racial Diversity: New Evidence From National Data (Job Market Paper, with Been)
Abstract
We study the role density zoning plays in neighborhood racial change with a new
spatial dataset of regulatory borders. Combining geocoded property records with
estimates of minimum lot size restrictions within U.S. cities, we identify the
borders of areas where sharp shifts occur in the maximum allowable residential density.
Merging that border data with the demographics of Census blocks on each side of the
border, we estimate how minimum lot sizes contribute to differences in the racial
diversity of neighborhoods. We find that the effects minimum lot sizes have on racial
diversity vary significantly, depending on the urban context. Effects are strongest
in areas of higher density suburban development. There, lot size restrictions that
decrease density by 2 units per acre relative to areas on the other side of the
regulatory boundary cause sizable declines in diversity. Effects fade when one or more sides
of the boundary has minimum lot requirements above a quarter acre in effect. Our results
show the circumstances in which lot size regulations stymied racial integration and
persistently hindered fair housing goals in the following decades.