US cities became increasingly segregated by race over the 20th century. General consensus holds that most of this segregation was concentrated in the post-war period. This column uses neighbourhood-level data to find that racial segregation in cities began earlier; indeed, much of it had taken place by 1930. The column also examines the residential response of whites to black arrivals, suggesting that this contributed to segregation in addition to discrimination and institutional factors.
Over the 20th century, US cities became increasingly segregated by race. Existing scholarship on the role of ‘white flight’ has focused on post-war suburbanisation, for instance by documenting the importance of highways in enabling whites to leave central cities (Baum-Snow 2007). Furthermore, economists and sociologists have argued that whites left neighbourhoods in response to black arrivals in the post-war decades, generating the distinctive American urban pattern of blacks residing in the urban core with whites populating the suburban periphery (Massey and Denton 1993, Boustan 2010).
In new research, we argue that whites began resorting themselves away from black arrivals in the first decades of the 20th century, decades before the opening of the suburbs (Shertzer and Walsh 2016). Our analysis isolates the channel of white flight from institutional barriers that constrained where blacks could live in cities. We argue that accelerating white population departures in response to black arrivals at the neighbourhood level can explain up to 34% of the increase in segregation over the 1910s and 50% over the 1920s. Importantly, our analysis suggests that, while discriminatory institutions faced by blacks were clearly important, segregation may have emerged in US cities even in their absence simply as a consequence of market choices made by white families.