California Reaped Large Savings by Diverting Drug-Using Offenders Into Treatment

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A California law that allows qualified drug offenders to enter substance use treatment rather than go to jail or prison saved the state close to $100 million in its first year, NIDA-supported researchers report. Dr. M. Douglas Anglin and colleagues at the University of California, Los Angeles estimated that California spent an average of $2,300 less on each of 42,000 offenders who were adjudicated under its Substance Abuse and Crime Prevention Act of 2000 (SACPA; also known as Proposition 36) than it would have spent without the Act. The savings mainly reflected reduced spending on incarceration, which outweighed the cost of extending treatment to more offenders.

SACPA provides that individuals convicted for the first or second time on charges related to personal drug use are eligible for parole conditioned on participation in a licensed substance abuse treatment program. To qualify for SACPA, offenders must not have any current nondrug charges or previous or current charges for violent behavior. SACPA does not require patients to meet criteria for motivation or suitability for treatment, and therefore is more broadly inclusive than drug courts and other programs to divert drug offenders from the correctional system.

The economic rationale for SACPA is the idea that rerouting offenders from jail or prison to parole and treatment should lower the state’s costs. To see whether SACPA achieved this goal, Dr. Anglin’s team tallied California’s expenditures on health, criminal procedures, and substance use treatment for all offenders adjudicated under SACPA from July 1, 2001, through June 30, 2002. They compared these figures with the outlays for 47,000 drug offenders who were convicted from July 1, 1997, through June 30, 1998, and would have been eligible for SACPA if it had existed then.

The offenders’ costs to the state were higher in both groups during the 30 months after their convictions than during the 30 months before their convictions, when some were not yet involved in the treatment or the criminal justice system. The researchers estimated that the state’s post-conviction cost increases averaged $8,300 per SACPA-adjudicated offender, compared with $11,300 per pre-SACPA offender.

Figure. In California, Treating Drug Offenders Is Cost Effective California’s criminal justice and public health expenditures increase when the state convicts an individual on a drug charge and mandates him or her to incarceration or treatment. The amount of this increase was estimated to be $2,300 less, on average, per offender in the first year of SACPA than in a comparable period before SACPA (“Total”). The SACPA advantage mainly reflected savings from incarcerating fewer individuals (“Prison/Jail”), which more than offset the cost of extending treatment to more individuals (“Treatment”).

Text description for Figure

The y-axis of the graph in this figure shows differences in costs in U.S. dollars per drug offender during 30 months pre-conviction versus 30 months post-conviction. The x-axis shows the domains of these costs, that is, jail/prison, treatment (for drug use), parole, probation, and arrest, as well as the total of all costs. The costs are shown for offenders in the SACPA program (purple bars), offenders before SACPA implementation (used as a control; blue bars), and as the difference between the two groups (orange bars). For example, jail/prison resulted in costs that were higher for the control group than for the SACPA group, resulting in a negative cost difference indicating that the SACPA program saved costs in this domain.

The major source of savings under SACPA was an average $6,000 smaller rise in post-conviction incarceration costs per offender, realized in large part because many SACPA offenders who would have gone to prison before SACPA stayed out on parole (see Figure). This economic benefit was partially offset by the cost to treat more offenders under SACPA, leading to a $1,400 greater rise in the post-conviction treatment cost in the SACPA group than in the pre-SACPA group. Because SACPA offenders who were placed on parole remained exposed to re-arrest, the state’s costs related to new arrests went up $1,600 more in the SACPA group than the pre-SACPA group.

After combining these numbers and taking into account other minor related costs, the researchers concluded that SACPA yielded an average net reduction of $2,300 in post-conviction cost increases per offender. Other studies have shown that treatment in lieu of incarceration reduces repeat criminal offenses and drug use over the longer term, suggesting that SACPA results in additional savings not captured by this study.

Because of budgetary decisions, California eliminated SACPA’s funding after 2010. Although eligible offenders can still opt for drug treatment, Dr. Anglin says that it’s unclear whether SACPA programs will be able to continue without designated funds.

Dr. Anglin and colleagues point out that the costs of substance use to communities have strongly increased in recent years, and the fastest growing costs are those for criminal justice activities. SACPA, the researchers say, shows that apportioning funding to treatment rather than incarceration for nonviolent drug offenders reduces costs while providing outcomes that are comparable to those achieved through regular substance use treatment programs.

This study was supported by NIH grant DA016383.


Anglin, M.D., et al. Offender diversion into substance use disorder treatment: the economic impact of California’s Proposition 36. American Journal of Public Health 103(6):1096-1102, 2013. Abstract