Costs of jail diversion for persons with mental illness: A case study

In 2003 Bexar County, Texas (United States of America), fully implemented a jail diversion program (“BCJD”) for persons with mental illness that, unusually, incorporates both major components of diversion, a pre-booking component and a post-booking component. Although jail diversion programs are gaining in popularity, there is little evidence on the trade-offs among the resources required to help individuals.

This study reviews the evidence of the costs and benefits of such programs to date. Using data on the BCJD it also presents fresh evidence on the costs of jail diversion; and how the associated costs shift between agencies.

The study takes the perspective of Bexar County public organizations. Micro-costing techniques were used to gather information on the cost of jail diversion. Administrative data systems were used to gather individual-level information on resource use and outcomes. The diverted sample of people was diverted from jail during the period September, 2003, to September, 2005. A comparison sample was created by sampling people in Bexar County from the period immediately before the BCJD initiative began (1999 to 2001). These people would have been diverted from jail had a formal diversion program existed at the time.

Jail diversion represents an opportunity to assess, intervene, and treat a needy population. Evidence to date suggests that the associated short-term increase in healthcare costs may be off-set by reductions in criminal justice costs. Because this program contains the two common types of diversion in the same program, the findings from this study will be broadly applicable.