The decennial census counts individual people in their primary residence, but what happens to people who are living in group settings, such as those individuals currently in prison? How do they get counted and included in the census? Where can you find the data? What needs to be taken into consideration when using the data?
Who gets counted?
By the U.S. Census Bureau’s definition, what is commonly referred to as “prison population” is a subcategory of the “Group Quarters population”. To understand who is counted in the “prison population”, and where to find the right table with the data point you are interested in, it’s essential to get familiar with a series of concepts related to the “Group Quarters”.
Group Quarters, or GQs, are residential locations that are different from typical residential places such as houses, apartments, and mobile homes. Residents who live in group quarters receive housing and other services from an organization, but they aren’t usually related to each other like family members. Group quarters include prisons, as well as college residence halls, residential treatment facilities, skilled nursing facilities, group homes, military barracks, and work dormitories. All of these combined contained roughly 3% of the total population in the U.S. in 2020. And Census Bureau staff visited about 271,000 Group Quarters for the 2020 Census.
Populations in prison are recorded in the subcategory of “Correctional Facilities for Adults”, under the category of “Institutional Group Quarters”. Besides correctional facilities for adults, it also includes juvenile facilities, (skilled) nursing facilities, and other institutional facilities.
“Correctional Facilities for Adults” consist of federal detention centers, federal and state prisons, local jails and municipal confinement facilities, correctional residential facilities, as well as military disciplinary barracks and jails. You can find more detailed definitions of these facilities here. It’s important to know what facilities are included in the “Correctional Facilities for Adults” category since this is the most detailed level of prison population count provided by the Census Bureau.
Generally, on Census Day, prisoners are counted at their facility; however, the Census aims to count the people at the right place, namely, where people usually live. By the rule of “usual residence”, only people who have spent most of their time in the past year living and sleeping in the correctional facilities should be counted in the “prison population”. Therefore, some adjustments may take place for:
- Prisoners who are in short-term jails
- Prisoners who are waiting for a hearing
- Prisoners in hospitals for a short-term stay
- Any other prisoners who don’t fit the “usual residence” rule
These prisoners are usually directed to be counted among their usual residence before their imprisonment.
Additionally, according to the same rule, if a prison staff member doesn’t have a usual home elsewhere, they are counted at the facility as well.
Where to find the prison population data?
On Sep. 16, 2021, the Census Bureau released the 2020 Census Public Law 94-171 Redistricting Data (PL), and “prison population” is included in the subcategory “Correctional Facilities for Adults” in the table “P5: Group Quarter Population by Major Group Quarter Type”, which is available down to the block level for the U.S and Puerto Rico.
(Click here to view the data for Detroit on data.census.gov)
Sample fig. 1: A Snapshot of the 2020 P5 Table
The following files can be used as a reliable reference for a historical prison population count:
- In the 2010 DEC SF (Decennial Summary File), Table “P42: Group Quarters Population by Group Quarter Type” has a population count for “Correctional facilities for adults”, which is also available down to the block level. Table “P43: Group Quarter Population by Sex by Age by Group Quarter Type” provides more demographic information related to the prisoner population.
- In the American Community Survey, tables with codes beginning with B261 also contain population counts and demographic details for the subcategory “Adult correctional facilities”; however this series of datasets are only available at the national, divisional, regional, and state level, from 2017 to 2019, for 1 year and 5-year estimates:
Learning about the prison population can be important for various reasons. For instance, it is sometimes argued that the communities around prisons unfairly benefit from the counted prisoners, even though the prisoners didn’t enjoy the benefits of increased funding and programming that the census counts provide to the area. Also, it’s important to understand when the prison population is counted in a survey, and when it is not. For example, if you are interested in the poverty-related data, it may be helpful to know that the American Community Survey’s estimate of poverty actually excludes people living in the institutional Group Quarters, which include people in prisons.
If you have any questions about the prison population in Metro Detroit or need any data collection assistance, please feel free to submit an AskD3 request.