The Emergence of Exclusionary Zoning Across American Cities (Job Market Paper)
This paper identifies how Black migration into American cities caused
their suburbs to adopt a widespread land use control --- minimum lot sizes.
I develop an algorithm detecting bunching on lot sizes, observable when governments'
lot size controls bind developers from building denser housing. Applying the algorithm to national
assessor records, I estimate for 7,000 local governments which lot size controls
first came into effect and how they limited residential density over the last 80 years.
Most suburbs adopted lot size controls from 1945--1970, the same period when four million
Black Americans left the South for economic opportunity. I then use the
``Second Great Migration'' as a natural experiment that shifted central cities'
racial composition toward Black Americans. From 1940--1970, the rise in central city
Black composition in non-Southern central cities accelerated minimum lot size
adoption while further explaining binding density controls applied to at least 830,000 housing units.
Migration of lower-income whites into the same cities instead cause small and negative effects on suburban lot size outcomes.
In states that passed early legislation to desegregate public schools, Black migration
had the largest effects on lot size restrictiveness. Together, the results indicate that
local governments designed land use controls to exclude Black migrants from neighborhoods and public goods.