Distinguishing the Levels and Dimensions of . . .

Drawing on decennial census data, we assess trends in residential segregation in the United States from 1960 to 2000 along several dimensions of ancestry, class, and life cycle. To do so, we develop a methodology for attributing segregation to several nested geographical levels. Segregation for metropolitan America is measured using the Theil index which is additively decomposed into contributions of regional, metropolitan, center city-suburban, place, and tract segregation. This allows us to distinguish whether groups live apart because members cluster in different neighborhoods, communities, or even metropolitan areas and regions, and how those patterns have changed. We find that the segregation of blacks decreased substantially over the 40 years largely because neighborhoods became more integrated, but the foreign-born became more segregated largely because they concentrated in particular metropolitan areas. Class segregation increased after 1970, mainly because the affluent clustered together more in both specific metropolitan areas and in specific municipalities within metropolitan areas. The unmarried increasingly congregated in center cities. The main purpose of this paper is to describe and illustrate this multi-level approach to studying segregation. In 1996, Douglas Massey dramatized a concern shared by many scholars of urban inequality: that Americans are moving into an "age of extremes" in which disparities of wealth and power increasingly produce and are reinforced by spatial separation. With the growth of gated communities for the affluent and the further ghettoization of the poor, the United States is becoming more and more fragmented, he argued. An even wider concern is that, across various dimensions of difference, such as class, ancestry, and life cycl..