Racial Sorting and the Emergence of Segregation in American Cities

Residential segregation by race grew sharply during the early twentieth century as black migrants from the South arrived in northern cities. The existing literature emphasizes collective action by whites to restrict where blacks could live as the driving force behind this rapid rise in segregation. Using newly assembled neighborhood-level data, we instead focus on the role of “flight” by whites, providing the first systematic evidence on the impact of prewar population dynamics within cities on the emergence of the American ghetto. Leveraging exogenous changes in neighborhood racial composition, we show that white departures in response to black arrivals were quantitatively large and accelerated between 1900 and 1930. Our preferred estimates suggest that white flight can explain 34 percent of the increase in segregation over the 1910s and 50 percent over the 1920s. A key implication of these findings is that segregation could have arisen solely as a consequence of flight behavior by whites.