Skip to main content

The FRED® Blog

The American racial patchwork Measuring racial diversity across U.S. counties


The U.S. population is a patchwork of all sorts of immigrants and nationalities, which also translates into wide racial diversity. But the degree of diversity isn’t uniform across the country, which we can see if we examine the “racial dissimilarity index” shown on the map.” Here’s the story. The Census Bureau has data from the 3,241 U.S. counties that divide the population into White and Non-White, with a national average of 78% White and 22% Non-White. They create an index that basically depicts how diverse the racial distribution of the population is within each county: They determine the proportion of each group for each county and adjust each county’s score according to the share of its non-Hispanic White population that would have to move from one census tract in that county to another census tract to achieve uniformity across tracts. (Each census tract typically has a few thousand people.) This score appears to vary widely from county to county, showing that even neighboring counties can have very different racial landscapes. Also keep in mind that two counties could have essentially the same score but be mirror images of racial dissimilarity. Take Allamakee County, Iowa, and Bolivar County, Mississippi, for example. Their dissimilarity scores are very close (66.34 and 58.03), but their populations don’t look the same. The United States really is a patchwork.

How this map was created: Go to GeoFRED and select the county maps. Look for “White to Non-White Racial Dissimilarity” in the dropdown menu.

Suggested by Christian Zimmermann.



Subscribe to the FRED newsletter


Follow us

Twitter logo Google Plus logo Facebook logo YouTube logo LinkedIn logo
Back to Top