Explaining changes in US residential segregation through patterns of population change

While overall residential segregation in US cities has declined in the past 30 years—especially between the Black and white populations—relatively little is known about the patterns of population change that caused these changes. Here I investigate changes in racial residential segregation in US cities between 1990 and 2020, and focus on answering two key questions: first, which racial groups are driving changes in segregation, and second, where in the metropolitan area these changes are produced. By connecting segregation to population changes in specific locations, this study highlights how segregation is connected to core urban problems and processes such as suburbanization, gentrification and other forms of spatial inequality in cities. To answer these questions, the paper develops a flexible decomposition method that allows us to draw a direct link from changes in the distribution of racial groups—brought about by residential mobility, births and deaths—to changes in racial segregation. This demographic approach to explaining segregation change quantifies how much Black suburbanization, 'white flight' and other group-specific population changes contribute to changes in segregation. The results show that almost all decreases in segregation were produced by the suburbanization of Black, Hispanic and Asian people, as well as the population growth of these groups in the formerly majority white areas of central cities. Changes in the distribution of the white population, instead, are mostly associated with increasing segregation. Hence, segregation has decreased despite the majority group's efforts to resegregate themselves. The upshot is that most metropolitan areas are shaped by simultaneous and ongoing desegregation and resegregation ('racialized reshuffling'), and that this process is not restricted to the difference between central cities and suburbs. For the white population, both growth and decline in suburban places contributed toward increasing segregation, which indicates that there is substantial resorting happening also within suburbs. The results of this study suggest that focusing only on the integration of minority populations, without also limiting the resegregation of the white population, will be ineffective in bringing about substantial reductions in segregation. This paper investigates changes in racial residential segregation in US cities between 1990 and 2020 with a flexible decomposition method. It finds that almost all decreases in segregation were produced by the movement of Black, Hispanic and Asian people while changes in the distribution of the white population were mostly associated with increasing segregation. Hence, segregation has decreased despite the majority group's efforts to resegregate themselves.