To end mass incarceration, focus on crime reduction
However, during my years in the criminal justice reform movement, I have come to believe that merely ratcheting back punishment severity—without simultaneously increasing the probability of punishment for people who commit crimes—is both bad policy and bad politics. Meaningful decarceration will not be easy or quick, and it will require difficult tradeoffs. Most importantly, strong and consistent evidence suggests policies that emphasize certain punishments will deter crime in ways that randomly imposed severe penalties can’t. The key is to create credible threats that criminal behavior will be punished. Doing so will result in fewer crimes committed, and therefore fewer necessary punishments.