The unprecedented surge in incarceration since 1980 has stimulated a national debate between those who claim that locking up over 2 million people is necessitated by public safety concerns, and those who say the human and financial burden of imprisoning so many of our citizens is intolerable.

But framing the incarceration debate as a tradeoff between public safety and public finance is far too narrow. The best evidence suggests the prison population would be substantially reduced with negligible effects on crime rates. Crime could actually be reduced if the savings were put to use in strengthening other criminal justice programs and implementing other reforms. Making this case requires that we confront widespread skepticism about the possibility of reducing criminal behavior on the outside.

The research community has made real progress in identifying the causal effect of various crime-related policies in recent years, providing us with proven alternatives to prison for controlling crime. The key has been to make greater use of experimental methods of the sort that are common in medicine, as well as “natural experiments” that arise from naturally occurring policy or demographic shifts.

via More Prisoners Versus More Crime is the Wrong Question – Brookings Institution.