Nearly two million adults were incarcerated across the country, according to the 2020 Decennial Census. The latest figures show a 13% drop in the total number of incarcerated people, or nearly 300,000 fewer people, compared with the 2010 Census.

Roughly one-third of the drop in total numbers occurred in just two populous states — California and New York. In total, 41 states, the District of Columbia and Puerto Rico saw reductions in the total number of incarcerated people.

In five states, the number of incarcerated people actually increased compared with a decade ago, but the incarceration rate still shrank because their total population grew more quickly than the prison population. Just four states — West Virginia, Alaska, Nebraska and Arkansas — saw their incarceration rate increase.

The most consequential function of the census — in fact, the reason the constitution mandates a census every ten years — is to divide state populations into roughly equal legislative districts. This has profound ramifications for incarcerated people because in most states, they are counted in the places where they are held, not in the communities where they are from. 

The practice, dubbed “prison gerrymandering,” dilutes the political power of urbanized areas — where many incarcerated people come from — and adds to the political power of rural areas where prisons, jails and detention centers are often located.

Since incarcerated people in the vast majority of states are denied the right to vote, these rural areas gain political representation from incarcerated people who are virtually excluded from civic life.

Confusingly, even those incarcerated people who can vote in Maine and Vermont, do so with an absentee ballot from their pre-incarceration precinct, despite being counted as residents of wherever they are incarcerated at the time of the Decennial Census.

Twelve states ended the practice before drawing up new districts in 2021, and will count incarcerated people in their home district moving forward.

Incarceration in Most States Stayed Relatively Flat

In most states, the raw numbers of incarcerated people didn’t change much, despite widespread efforts to decarcerate prisons and jails during the COVID-19 pandemic.

Instead, a few populous states lost a larger share. For example, California’s incarcerated population shrunk by 50,000, and New York’s by 30,000. Together, they account for approximately one-third of the national decrease in incarcerated population, while representing less than one-fifth of the country’s population. Nine states saw an increase in the incarcerated population.

Read the full article about incarceration in America by Weihua Li, David Eads, and Jamiles Lartey at The Marshall Project.