We study the causal effect of incarceration on reoffending using discontinuities in North Carolina’s sentencing guidelines.
A regression discontinuity analysis shows that 1 year of incarceration causes a reduction in the likelihood of being reincarcerated within 3, 5, and 8 years from sentencing by 44%, 29%, and 21%, respectively. To parse the potentially heterogeneous dose-response relationship underlying these effects, we develop an econometric model of prison sentences and recidivism. We find that incarceration has meaningful reoffending-reducing average effects that diminish in incarceration length. As a result, budget-neutral reductions in sentence length combined with increases in incarceration rates can decrease recidivism. (Publisher abstract provided)