Scott analyzes research on whether longer prison sentences reduce crime, examining studies on deterrence, incapacitation, and aftereffects, to conclude that while prison does decrease crime through incapacitation, it's less cost-effective than other methods like policing. Longer summary

This post examines the relationship between prison sentences and crime reduction through three mechanisms: deterrence (scaring potential criminals), incapacitation (preventing prisoners from committing crimes), and aftereffects (post-release behavior changes). Through analysis of multiple studies and reviews, Scott finds that deterrence effects are minimal, incapacitation has strong positive effects (preventing about 7 crimes per prisoner-year), and aftereffects range from slightly beneficial to harmful depending on circumstances. He concludes that while prison does reduce crime, with a 10% increase in incarceration reducing crime by about 3%, it's less cost-effective than alternatives like increased policing. The post ends by examining practical challenges in the justice system that prevent effective handling of repeat offenders. Shorter summary