Projecting the impact of new sentencing laws on prison populations

Recent efforts at sentencing reform have led to the consideration or enactment of new sentencing structures, including mandatory-minimum sentences, flat-time sentences, and sentencing guidelines. There is a clear need for estimates of the impacts that new sentencing laws would have on sentencing practice and on corrections programs, both as an informational input during legislative debate and as a basis for planning once a particular law is enacted. This study develops a methodology for estimating the impacts of alternative sentencing policies on prison populations. The methodology is demonstrated with an estimation of the impacts on the Pennsylvania state prison system of a mandatory-minimum sentencing bill which was considered by the Pennsylvania legislature.This research was supported in part by SPC No. 568788 funded by the Pennsylvania Governor's Justice Commission. The assistance of the Governor's Justice Commission, the Pennsylvania Association of Probation, Parole, and Correction, the Pennsylvania Bureau of Correction, the Pennsylvania Department of Education, and the Subcommittee on Crime and Correction of the Pennsylvania House Judiciary Committee in providing data and information is gratefully acknowledged. Appreciation is also due to Alfred Blumstein and Patrick Larkey for providing helpful comments on an earlier draft of this paper.