U.S. Prison Population Trends 1997-2017: Massive Buildup and Modest Decline

By yearend 2017, 1.4 million people were imprisoned in the United States, a decline of 7% since the prison population reached its peak level in 2009. This follows a nearly 700% growth in the prison population between 1972 and 2009.

The overall pace of decarceration has varied considerably across states, but has been modest overall. Thirty-nine states and the federal government had downsized their prisons by 2017. Five states—Alaska, New Jersey, Vermont, Connecticut, and New York—reduced their prison populations by over 30% since reaching their peak levels. But among the 39 states that reduced levels of imprisonment, 14 states downsized their prisons by less than 5%. Eleven states, led by Arkansas, had their highest ever prison populations in 2017.

If states and the federal government maintain this pace of decarceration, it will take 72 years—until 2091—to cut the U.S. prison population in half.

The United States has made only modest progress in ending mass incarceration despite a dramatic decline in crime rates. Reported crime rates have plummeted to half of their 1990s levels—as they have in many other countries that did not increase imprisonment levels. Expediting the end of mass incarceration will require accelerating the end of the Drug War and scaling back sentences for all crimes, including violent offenses for which half of people in prison are serving time.

U.S. Prison Population Trends: 1999-2017

Incarceration trends vary significantly among the states. By 2017, 39 states had at least modestly downsized their prison populations from their peak levels. Five states led the nation in reducing their prison populations by 30% or more:

• Alaska (39% decline since 2006)¹
• New Jersey (38% decline since 1999)
• Vermont (35% decline since 2009)
• Connecticut (33% decline since 2007)
• New York (32% decline since 1999)

Some Southern states, which have exceptionally high rates of incarceration, also achieved double-digit percentage reductions in their prison populations since reaching their peak levels. Specifically:

• Alabama (25% decline since 2012)²
• South Carolina (17% decline since 2009)
• Louisiana (16% decline since 2012)
• Mississippi (15% decline since 2008)

The federal prison population declined in size by 16% between its peak in 2011 and 2017—at over twice the nationwide rate of decarceration. The number of people held in federal prisons has since continued to decline.

These prison population reductions are the result of a mix of changes in policy and practice designed to reduce prison admissions and lengths of stay. While some critics have charged that decarceration would lead to rising crime, states with the most substantial reductions in their prison populations have often outpaced the nationwide crime drop. This pattern is most pronounced in New York State, driven by changes in New York City. Between 1999 and 2017, the state downsized its prison population by 32% while the nationwide level of imprisonment increased by 10%. Meanwhile, New York’s declines in reported rates of murder, violence, and property crimes during this period far outpaced the nationwide crime drop.

But overall, the pace of decarceration has been slow in most states. In 14 states the prison population reduction was less than 5%. Texas and Florida, which rank first and third highest among states in the size of their prison populations, have downsized their prisons by just 4% and 6%, respectively, since reaching their peak levels.³ Eleven states had not achieved any prison population reductions by 2017, even though most are experiencing reported crime rates that are far below their peak levels. Among these states, the largest 5-year increases in prison populations since 2012 have occurred in Arkansas, with a 23% increase. Washington, Wyoming, Wisconsin, and Kentucky have also grown their prison populations by 10% or more during this five-year period.

Expediting the end of mass incarceration

Growing recognition of the scale and urgency of mass incarceration is now reflected in the work of leaders as diverse as Sen. Cory Booker and former House Speaker Newt Gingrich. A growing number of policy experts and advocacy organizations are now calling for a 50 percent reduction in the U.S. prison population within the next 15 years. These include the ACLU and JustLeadership USA.

But the sobering reality is that at the pace of decline since 2009, averaging 1% annually, it will take until 2091—72 years—to cut the U.S. prison population by 50%.

Clearly, waiting seven decades to substantively alter a system that is out of step with the world and is racially biased is unacceptable.

Expediting the end of mass incarceration will require intensifying sentencing reforms for non-violent crimes and making a meaningful dent into the number of people imprisoned for violence. Past reforms have helped to reduce the number of people imprisoned for a drug offense by 26% between peak year 2007 and 2016. The number of people imprisoned for a property offense has declined by 14% between peak year 2007 and 2016.

But for the half of the prison population imprisoned for a violent crime—which ranges from certain burglaries, robbery, and assault to rape and murder—reforms remain the exception. Overall, the number of people imprisoned for a violent offense has only declined by 2% between peak year 2009 and 2016. The reluctance to scale back excessive sentences for this population is at odds with evidence that long sentences incapacitate older people who pose little public safety threat, produce limited deterrent effect since they do not increase the likelihood of arrest, and detract from more effective investments in public safety.

Ending mass incarceration within our lifetime requires bold leadership to accelerate the pace and scope of reforms.