The Origins of Urban Segregation in the United States.

• Author: Shertzer, Allison
• Position: Research Summaries

Segregation by race is a central and persistent characteristic of American cities, and there is a broad consensus among economists that this spatial separation of racial groups is a key driver of socioeconomic outcomes for urban Americans. Researchers have documented that segregation contributes to poverty, adverse educational outcomes, and reduced intergenerational mobility. (1)

These findings naturally give rise to a focus on the origins of segregation. Attention has concentrated on three potential mechanisms: uncoordinated individual behavior, collective group action, and government policy, all of which have the potential to overlap and mutually reinforce one another. In this research report, we describe our work on the rise of segregation in pre-World War II American cities. We focus on the early 20th century period during which black ghettos were established or consolidated in most northern urban areas. The decades from 1900 to 1930 saw the largest increases in measured segregation of the century, as black migration from the South accelerated due to a combination of factors such as the boll weevil's devastation of Southern cotton crops and the slowdown of European immigration after World War I.

Despite the importance of this era for understanding how American cities came to be segregated, it has been the focus of very little empirical work in economics. This lack of attention stems from the absence of finely detailed spatial demographic data on cities for time periods prior to 1940. We have recently constructed such a dataset. It covers 10 major cities and was built by digitizing maps of census enumeration districts and matching them to the full-count census data from 1900, 1910, 1920, and 1930. (2) The resulting dataset gives us new opportunities to study urban population dynamics in prewar America.

The Role of White Flight

Recent scholarship in law and history argues that the federal government played a key role in segregating American cities, for instance by "redlining" potentially integrated neighborhoods when issuing mortgage insurance policies beginning in the mid-1930s. (3) While these government actions may have been important for maintaining the color line in the postwar era, there exists little empirical support for the notion that government intervention was crucial for the initial establishment of segregated neighborhoods. Given that contemporary urban economics literature highlights how uncoordinated, intra-city household sorting across urban areas can increase segregation by race, (4) it is natural to ask: is it possible that segregation could have arisen even in the absence of discriminatory federal policies?

To answer this question, we use our new neighborhood-level dataset to quantify the extent of "white flight" from neighborhoods receiving black in-migrants. (5) Using methods from the labor economics literature to obtain exogenous variation in where black migrants settled, (6) we argue that white households departed neighborhoods in reaction to black arrivals at an accelerating rate over the 1900-30 period. Using a...