This is what the final metric, the integration-segregation index, gets at. It’s defined by the relationship between citywide and neighborhood diversity scores. If we graph the 100 most populous cities on a scatterplot, they look like this:
The integration-segregation index is determined by how far above or below a city is from the regression line. Cities below the line are especially segregated. Chicago, which has a -19 score, is the most segregated city in the country. It’s followed by Atlanta, Milwaukee, Philadelphia, St. Louis, Washington and Baltimore.
Cities above the red line have positive scores, which mean they’re comparatively well-integrated. Sacramento’s score is a +10, for instance.
But here’s the awful thing about that red line. It grades cities on a curve. It does so because there aren’t a lot of American cities that meet the ideal of being both diverse and integrated. There are more Baltimores than Sacramentos.
Furthermore, most of the exceptions are cities like Sacramento that have large Hispanic or Asian populations. Cities with substantial black populations tend to be highly segregated. Of the top 100 U.S. cities by population, 35 are at least one-quarter black, and only 6 of those cities have positive integration scores.
So perhaps the Chicago School was correct: it is really neighborhoods that matter, even within cities with millions of people. This is what an interesting recent map of Detroit showed where there are clearly clusters of the city that have traditional neighborhoods while other parts are more vacant urban prairies. The sociological literature on poor neighborhoods that emerged starting in the 1970s gets at a similar concept: there are unique conditions and processes at work in such neighborhoods. And, Silver’s analysis confirms sociological research on residential segregation that for decades (perhaps highlights most memorably in American Apartheid) has argued that black-white residential segregation is in a league of its own.
Based on this kind of analysis, should sociologists only use city-wide or region-wide measures of segregation in conjunction with measures or methods that account for neighborhoods?