Prison And Crime: Much More Than You Wanted To Know

Abstract

A comprehensive analysis of the relationship between incarceration and crime rates reveals that prison sentences reduce crime primarily through incapacitation rather than deterrence. Each year of imprisonment prevents approximately seven crimes (six property crimes and one violent crime), though this effect varies by context and diminishes with higher incarceration rates. Deterrence effects are minimal, with each additional year of threatened sentence reducing crime by only about 1%. While some researchers argue that prison’s criminogenic aftereffects cancel out the benefits of incapacitation, most evidence suggests these effects are modest for longer sentences, though potentially significant for shorter ones. At current U.S. margins, a 10% increase in incarceration reduces crime by about 3%. Cost-benefit analyses yield mixed results: imprisonment barely breaks even under the most favorable assumptions and is likely net negative when accounting for costs to prisoners. More cost-effective alternatives exist, particularly increased policing, which prevents about 50 crimes per officer annually compared to 7 crimes prevented per prisoner-year. The practical challenge of prosecuting repeat offenders stems primarily from resource constraints in the justice system rather than from legal or policy barriers. These findings suggest that while incarceration does reduce crime, untargeted sentence lengthening is neither the most effective nor the most cost-efficient approach to crime reduction. – AI-generated abstract