The effect of prison or jail sentences on recidivism is an important issue to those concerned with public safety and the cost-effectiveness of putting convicted offenders in prison. This paper summarizes theories and empirical studies on the effect of sentencing on recidivism. Study findings indicate that for some offenders, incarceration and longer confinement seem to increase the risk of recidivism. For other offenders, the likelihood of re-offense will either be unaffected or reduced by longer terms of incarceration. Furthermore, early-release programs do not appear to affect overall recidivism rates.