Contributing Empirical Evidence to a Policy Debate: A Researcher-Practitioner Collaboration Examining the Impact of Marijuana Decriminalization in Philadelphia on the Jail Population

• In Event: Research-Practitioner Partnerships in Philadelphia: Data-Driven Crime Reduction Efforts and Evaluation in Action

Abstract

In October 2014, Philadelphia formally decriminalized marijuana use, adding its voice to an increasing number of jurisdictions that debate legislative changes regarding recreational use of cannabis. This study is a researcher-practitioner collaboration between Temple and the Pennsylvania Department of Corrections that intends to inform the ongoing national debate on marijuana legalization with empirical evidence drawing on Philadelphia’s experience to date. Specifically, the study, using an interrupted time series design, examines the impact of the decriminalization policy in Philadelphia on the local jail population. Twelve-year worth of aggregate monthly counts of admissions and releases for marijuana-related offenses will be analyzed as the main dependent variables. To strengthen causal inferences and address validity threats, the study will also examine trends in: a) general/total admissions and releases pre- and post-intervention; b) correctional population serving sentences for other drugs and non-drug related offenses; and c) population trends in institutions in other comparable Pennsylvania counties not undergoing similar interventions. By focusing on a critical consequence of marijuana/drug policy—the impact on correctional capacity—the study will have relevance for the legalization debate on a wider scale, as the number of jurisdictions considering such policy changes continues to grow.

Authors

• E. Rely Vilcica, Temple University

• Bret Bucklen, Pennsylvania Department of Corrections