Does Mandatory Diversion to Drug Treatment Eliminate Racial Disparities in the Incarceration of Drug Offenders? An Examination of California's Proposition 36.

Objective: This paper addresses previous shortcomings in the literature on racial disparities in incarceration for drug offenders by taking advantage of a change in sentencing policy in California and a rich administrative dataset that is able to create a sample of comparable White and Black offenders. Method: We use a nonparametric propensity weighting approach to identify similarly situated White and Black male offenders charged with drug-related offenses. We combine this approach with a difference-in-differences model to estimate the effect that a change in California sentencing law for convicted non-violent drug offenders had on racial disparities in prison and drug treatment dispositions. Results: We find substantial reductions in the probability of a prison sentence after the policy change, but not differentially for Blacks. Blacks remain more likely to go to prison than similarly situated Whites after the policy, although the policy does lead to more referrals to treatment for Blacks. Conclusions: This paper shows that even after comparing Blacks and Whites in similarly situated contexts that racial disparities in prison commitments remain after sentencing law changes that mandate diversion to drug treatment. The results suggests that addressing racial gaps in the commitments to state prisons will likely require more than shifting the eligibility of drug convictions for prison, as accumulated criminal histories are the primary driver of prison sentences. This means that expanding diversion options from prison alone will not reduce the racial gap in commitments to prison for drug offenses more than incrementally.