Date: September 23, 2021
The highly anticipated release of local data from the 2020 Census showed that the United States is more racially and ethnically diverse than it has ever been. To measure this at a local level, we take a county-by-county look at the Census Bureau’s Diversity Index (DI). Our analysis reveals that 96.1 percent of all U.S. counties experienced an increase in their population diversity between 2010 and 2020.
The DI, a new metric to quantify increases in diversity beyond simply counting up the number of non-White residents, shows the likelihood that two residents chosen at random in a given area will be of different races and/or ethnicities. By comparing the 2010 scores for each county with their 2020 scores, we can get a sense of which counties' populations diversified the most in the last decade.
Topping the list is Williams County, North Dakota, with its DI score more than doubled from just 17.1 percent to 42.0 percent. Williams County is one of the fastest growing counties in the country, thanks to a booming oil industry. From a population that was nearly completely non-Hispanic White in 2010, Williams County is now home to almost 3,900 Hispanic Americans and more than 2,000 African Americans. In 2020, nearly one in four residents in the county was Hispanic or non-White.
Meanwhile in Forsyth County, Georgia, in the Atlanta suburbs, a fast-growing Asian population has helped the county increase its DI score from 34.2 percent in 2010 to 55.2 percent in 2020. Today, Asian residents make up 18 percent of the county’s population, up from just 6.2 percent in 2010.
Another way to look at the DI is to rank counties by the rate of change in their DI scores between 2010 and 2020. In other words, measuring the relative change in DI from 2010 to 2020. The top counties in this respect are all sparsely populated counties. This is not surprising given that in highly rural counties with small populations, it takes a few new non-White or Hispanic residents to make the rate of change in their DI look high. To account for this, we restrict the list to counties with at least 10,000 residents to get a sense of where more significant changes are taking place.
Here we see that half of the counties on this list are in West Virginia, one of only three states to shrink in population between 2010 and 2020 (the other two were Illinois and Mississippi). Overall, West Virginia shrank by 3.2 percent, or more than 59,000 people, from 2010 to 2020. Nearly all of this population loss was seen among non-Hispanic Whites, who declined by almost 119,000. Growth among Hispanics and those of mixed-race backgrounds on the other hand helped soften the severity of this decline.
Preston County, West Virginia, which saw the greatest relative increase in its diversity among counties with 10,000 or more residents, was also only one of eight counties in West Virginia to not shrink. Preston County was also the only one on the list that experienced population growth between 2010 and 2020.
This suggests that in many counties, small increases in non-White or Hispanic residents are not able to cancel out losses among non-Hispanic Whites. These worrying demographic patterns threaten the economic and social stability of counties that rely on growing or stable populations to maintain their local economies and labor forces.
After digging deeper into the data, we find that diversity has increased in nearly every part of the nation, not just in cities and suburban communities that have seen significant growth in their Hispanic, Asian, and immigrant populations. Surprisingly, the latest data shows that even small, rural counties across the country have been diversifying as well.
To examine further, we invite you to explore the map below, which toggles between each county’s 2010 DI score, their 2020 DI score, and the change seen over the decade in between.