People really cared about their homes. Property values, indeed, may be influenced by the changing racial composition of an area. But values do not always change in the way some might expect, said William Yancey, a sociologist at Temple University. The key, he said, is stability. Yancey said of Philadelphia's changes.
Segregation usually is measured in two ways.
One tallies the percentage of people living isolated in neighborhoods composed overwhelmingly of people from their own racial or ethnic group. Another compares the racial or ethnic makeup of a town to the racial or ethnic makeup of its larger county. It looks at two groups at a time and is expressed as the percentage of one that would have to move to make the racial mixture equal. By the first measure, the proportion of African Americans living isolated in overwhelmingly black neighborhoods in major metropolitan areas fell slightly from 1990 to 2000, according to a study by researchers at Harvard University, Duke University, and the independent Brookings Institution. At the same time, the share of Latinos and Asians living in isolated areas rose dramatically during the decade, in part because of the influx of immigrants who tend to cluster together.