Sentence Length and Recidivism: A Review of the Research

In response to increasing concerns about jail and prison overcrowding, many officials and legislatures across the U.S. have undertaken different efforts aimed at reducing the prison population, such as reduced sentence lengths and early release of prisoners. Thus, there is currently a high degree of public interest regarding how these changes in policy might affect recidivism rates of released offenders. When considering the research on the relationship between incarceration and recidivism, many studies compare custodial with non-custodial sentences on recidivism, while fewer examine the impact of varying incarceration lengths on recidivism. This article provides a review of the research on the latter. While some findings suggest that longer sentences may provide additional deterrent benefit in the aggregate, this effect is not always consistent or strong. In addition, many of the studies had null effects, while none of the studies suggested a strong aggregate-level criminogenic effect. Overall, the literature on the impact of incarceration on recidivism is admittedly limited by important methodological considerations, resulting in inconsistency of findings across studies. In addition, it appears that deterrent effects of incarceration may vary slightly for different offenders. Ultimately, the effect of incarceration length on recidivism appears too heterogenous to be able to draw universal conclusions. We argue that a deepened understanding of the causal mechanisms at play is needed to reliably and accurately inform policy.