Segregation

Geographic research on segregation addresses both the processes by which groups of people become spatially isolated from one another and the resulting geographic patterns of isolation. Segregation occurs based on a variety of characteristics (e.g., race, ethnicity, class, gender, sexual orientation, age) and at different spatial scales (e.g., regions, cities, neighborhoods, schools). In practice, researchers have paid the greatest attention to residential segregation in urban environments based on race/ethnicity. A major focus in the United States has been on the sometimes extreme segregation of the black population, but there has also been attention paid to other groups. In Europe, evidence exists for varying degrees of segregation among certain populations, including South Asians and Afro-Caribbeans in Britain, North Africans in France, Turks in Germany, and Roma in Eastern Europe. An example of legally enforced segregation in South Africa was apartheid.

The causes of segregation are complex and vary considerably between contexts. In the United States, segregation of blacks has been attributed to discriminatory real estate and mortgage lending practices, “white flight” (i.e., the out-migration of whites from areas with growing minority populations), the intentional location of public housing in marginal areas, and other factors. Sometimes it is argued that patterns of racial concentration reflect a voluntary choice on the part of group members, but these explanations must be viewed with great caution. For example, recent research in Los Angeles suggests that of four populations interviewed (white, black, Asian, and Hispanic), blacks expressed the strongest preference for living in racially integrated neighborhoods, challenging the notion that the segregation of blacks is voluntary.

Several indexes are used to measure residential segregation, with the most common being the index of[Page 424] dissimilarity. This index, which ranges between 0 and 100, measures the extent to which two populations (e.g., Asians and whites, blacks and non-blacks) are evenly distributed across cities or metropolitan areas. Because most research in the United States relies on census data, the index often uses census tracts (census-defined subdivisions of cities or metropolitan areas) to represent places of residence. For a hypothetical metropolitan area that is 30% black and 70% non-black, an index of 60 means that either 60% of blacks or 60% of non-blacks would need to move to another tract for all tracts to achieve a balance equal to the metropolitan area as a whole (30% black and 70% non-black). By this measure, the most segregated U.S. metropolitan areas in 2000 included Detroit (84), Milwaukee (81), Gary (81), Chicago (78), Flint (77), Cleveland (77), Buffalo (76), Cincinnati (74), and Newark (74). Researchers often consider indexes below 30 to be low, between 30 and 60 to be moderate, and above 60 to be high, although this division is rather arbitrary. Studies using indexes of dissimilarity suggest that the segregation of American blacks increased steadily from 1890 until around 1970, with levels declining somewhat in most metropolitan areas since then (although extreme segregation persists in many places).