Objectives: To describe jurisdictional variation in the economic impact of the California Substance Abuse and Crime Prevention Act (SACPA; aka “Proposition 36”), a statewide diversion program that offered eligible drug offenders probation or continued parole with substance use disorder treatment in lieu of incarceration.
Methods: Administrative data were used to conduct multilevel, difference-in-differences analysis examining the effect of individual- and county-level variables on total service-utilization costs across eight domains over 30 months pre- and post-conviction.
Results: County-level variability in the severity of offender populations served under SACPA and in the level of collaboration between SACPA stakeholders contributed to cost variability. More severe populations and less effective stakeholder communication produced increases in costs.
Conclusions: Evaluating the economic impact of broad drug-offender diversion programs requires a multilevel approach that adjusts for the severity of offenders served and the effectiveness of stakeholder interactions.