This analysis uses census tract data to measure the segregation of the poor in U.S. metropolitan areas in 1970, 1980, and 1990. Two measures of segregation are used: the indices of dissimilarity and isolation.

The authors examine the relationship between economic restructuring in a metropolitan statistical area (MSA) and 1980-1990 changes in poverty rates in its census tracts. A summary indicator of economic restructuring, encompassing changes in employment/population ratios, shares of manufacturing employment, and shares of MSA manufacturing in a tract's county, is developed to explain why MSA restructuring is particularly distressing for blacks. Most poverty growth in predominantly black census tracts occurred in MSAs with greater restructuring, and each increment of restructuring was significantly associated with the poverty growth there. Black tracts in a central city with, or in a county with, a larger share of the MSA's manufacturing were most vulnerable.