Incarceration and Desistance: Evidence from a Natural Policy Experiment, North Carolina and South Dakota, 1995-2019

In order to investigate whether reductions to sentence length reduce recidivism and its related costs, the research team conducted two studies under the same NIJ grant.
In Study 1, the research team used a quasi-experimental approach to examine how sentence length influenced time to rearrest. Specifically, the team estimated an instrumental variable hazard model using variation stemming from the implementation of South Dakota's Public Safety Improvement Act of 2013 (SB70). SB70 was a major sentencing reform that reduced the likelihood of
incarceration and the length of sentence for certain non-violent offenses. The legislation was a response to high rates of incarceration and rising criminal justice costs with a particular focus on addressing individuals convicted of non-violent offenses. The goal was to improve public safety while reducing corrections spending. For grand theft below $5,000 and third-degree burglary, the reform reduced the severity of the felony class and the maximum allowed sentence length by 50% to 80%. Only certain offenses were subject to sentencing reductions such that unaffected offense types were included in the analysis as a comparison group.
In Study 2, the research team applied the logic of recurring event hazard models that predicted the probability of events over time with two distinct objectives: to identify desisters and to estimate the impact of life events on the longitudinal pattern of offending. Administrative data from the North Carolina Department of Public Safety (NCDPS) Division of Adult Correction were obtained to answer this research question. The team connected commonly used trajectory models to recurrent event survival models.
This collection contains only syntax files and documentation that were created for Study 1 (South Dakota). The P.I. codebook reflects the dataset that was created for analysis, though the data are not available. Please refer to the User Guide for more information. While Study 2's (North Carolina) methodology is described, please note that, excluding the NIJ Final Report, no Study 2 materials are available through ICPSR.