The U.S. Prison Population and the Census

Have you ever wondered how America’s growing prison population is counted? On PolicyMap, under Residential Homes and Buildings on the Real Estate Analysis tab, you can find data on the number of people housed in correctional facilities throughout the country. Released decennially as part of the Census’ Summary 1 files, the Bureau strives to count each person only once and in the correct place. The Census counts people according to the “usual residence rule,” which means that people are to be counted where they “live and sleep most of the time.” While determining usual residence is clear cut in most cases, with some special populations, such as military personnel, college students, and incarcerated individuals, it is a more complex task and has been subject to some debate over the years.

The map below shows the percent of the population living in correctional facilities for adults in 2010 by county. As you can see, in areas with a strong prison presence, the percentage of an area’s residence that is incarcerated can be quite high. The highlighted county is Crowley County, Colorado, over 30% of the population of is made up of incarcerated individuals and the neighboring county of Bent, CO.


Some take issue with the Census’ current approach, arguing that it can lead to distortions in demographic data and “misleading conclusions about the size and growth of communities” (Prison Policy Initiative). Critics, such as the Prison Policy Initiative, also maintain that the Census’ policy leads to prison-based gerrymandering and unequal distribution of voting power. While a movement exists to continue trying to get the Census to change its policies, some states, such as Maryland New York, have passed legislation to count incarcerated people at their home addresses for purposes of redistricting. For more on the potential impact of the Census’ policy on demographic data and research, see here.