Following over 3,000 patients receiving substance abuse treatment in California, Dr. Susan Ettner et al. calculated that while, on average, substance abuse treatment costs $1,583 per person, it is associated with a monetary benefit to society of $11,487.  The doctors studied methadone maintenance, outpatient and residential treatment facilities.  Over half of the societal benefits came from a reduction in crime and incarceration.  Dr. Ettner et al. calculated that over the 9 month study:

- Victimization costs dropped by $3,019 as a result of crime reduction. 
- The overall reduction in crime costs was $5,676 per treatment, and the overall reduction in incarceration costs per treatment was $1,788. 
- The average per capita increase in earnings was $3,352. 
- The overall ratio of benefits to costs was 7:1. 

The study states that the estimates are conservative, meaning overall monetary benefits could be even higher.  They conclude, therefore, that spending taxpayer dollars on substance abuse treatment is a wise investment.