How Has Proposition 47 Affected California’s Jail Population?

Proposition 47 reduced the penalties associated with certain drug and property crimes by preventing prosecutors from charging these offenses as felonies in most cases. The proposition passed with strong support from California voters in November 2014. In the months that followed, jail populations declined sharply, driven primarily by a reduction in individuals being held or serving time for Prop 47 offenses. Based on a sample of California county jail systems, we estimate a 50 percent decline in the number of individuals being held or serving sentences for Prop 47 offenses. This change drove an overall decline in the jail population of 9 percent in the year following the proposition’s passage.

Four key mechanisms drove this decline in the jail population. First, we find an immediate decline in new bookings on arrests and warrants for Prop 47 offenses, reducing the flow of individuals into the jail system. Second, we also see a decline in the number of convictions for these individuals. Third, we find the share of Prop 47 defendants receiving pretrial releases increased. Finally, we see a decline in the average length of stay for sentenced offenders, which resulted in less custody time.

While all counties under study experienced jail population declines after Prop 47, we find those counties with overcrowded jail facilities used some of this newly available jail space to house offenders they would have otherwise had to release early due to jail capacity constraints. This increased flexibility has resulted in a reduction in early releases for offenders with more serious charges.

Taken together, we find significant changes in the level and composition of those incarcerated in jails following the passage of Prop 47. These changes suggest there are important public safety trade-offs to consider in evaluating the proposition’s effects, including crime and recidivism outcomes for Prop 47 offenders and those with more serious charges. In addition, a key component of Prop 47-the reinvestment of state correctional savings in behavioral health treatments and other prevention programs-has not yet been realized. A complete assessment of the effects of Prop 47 will need to account for the role that these programs may play in improving public safety. This evaluative work will be essential in directing future policy efforts as California pursues effective and efficient criminal justice reforms.