inmate-penpal | US prisoner and inmate data

So, what percentage of the U.S. population is behind bars ? The answer: About 0.7% of the United States is currently in a federal or state prison or local jail. If this number seems unworthy of the term “mass incarceration,” consider that 0.7% is just shy of 1%, or one out of a hundred. And a little more context shows that this fraction is actually incredibly high.

Because talking about portions of a percentage can be confusing, this concept is more often expressed as a rate: The United States currently incarcerates 698 per 100,000 people. (The rate is out of 100,000, rather than 1,000 or 10,000, because back when incarceration was much rarer you needed a larger denominator to express the rate in whole numbers. But either way, these are all different ways of expressing the same percentage.)

In some ways, though, looking at the portion of a country that is incarcerated understates the sheer size of mass incarceration, because the denominator includes many groups that are infrequently incarcerated. For example, no toddlers, few adolescents, and not very many teenagers are incarcerated.

Age curve of youth in the juvenile justice system.

Rather than calculating how many people in the U.S. are incarcerated, you could calculate how many adults are incarcerated (0.88%), or how many working-age adults are incarcerated (1.07%). These statistics are rhetorically useful, but are often difficult to pair with compatible data from other countries, states or topics, so they’re not used very often.

There is another way to look at the scale and uniqueness of the U.S mass prisoner experiment: Less than 5% of the world’s population is in the United States, but 20% of the world’s prisoner population are right here:

Women’s incarceration has grown at twice the pace of men’s incarceration in recent decades, and has disproportionately been located in local jails. The data needed to explain exactly what happened, when, and why does not yet exist, not least because the data on women has long been obscured by the larger scale of men’s incarceration. Frustratingly, even as this report is updated every year, it is not a direct tool for tracking changes in women’s incarceration over time because we are forced to rely on the limited sources available, which are neither updated regularly nor always compatible across years.

Particularly in light of the scarcity of gender-specific data, the disaggregated numbers presented here are an important step to ensuring that women are not left behind in the effort to end mass incarceration.

Jails loom large in women’s incarceration

A staggering number of women who are incarcerated are not even convicted: a quarter of women who are behind bars have not yet had a trial. Moreover, 60% of women in jails under local control have not been convicted of a crime and are awaiting trial.

Aside from women under local authority (or jurisdiction), state and federal agencies also pay local jails to house an additional 12,500 women. For example, ICE and the U.S. Marshals, which have fewer dedicated facilities for their detainees, contract with local jails to hold roughly 5,600 women