"Our comparative analysis of U.S. prison population trends from 1999 to 2014 reveals significant variation across the country. Although 39 states have seen declines since reaching peak prison populations in the past 15 years, most of these decreases have been modest. Conversely, 11 states have continued to see rising imprisonment rates. These trends indicate that while the national decline in prison populations is a positive development, achieving substantial decarceration will require more sustained efforts.
Notably, 12 states have achieved double-digit declines since 1999, led by New Jersey (31%), New York (28%), Rhode Island (25%), and California (22%). Importantly, these reductions have been achieved without compromising public safety. In contrast, states like Nebraska and Arkansas have seen double-digit increases in their prison populations, with growth rates of 22% and 18% respectively since 2009, despite benefiting from the national decline in crime rates. These states have thus resisted the broader trend towards decarceration" (website).