"Carey and Finigan (2004) estimated the benefits and costs of the Multnomah County Drug Court in Portland, Oregon. They evaluated a sample of 1,173 individuals to determine the cost and criminal justice outcome differences between the drug court and the business-as-usual process over a 30-month period following the initial court appearance. Based on their cost and benefit estimates, the benefit-cost ratio associated with Multnomah County Drug Court was 2.5.
"In an unpublished report, Harrell, Cavanaugh, & Roman (1999) estimated benefit-cost ratio of about 2 for the sanctions docket program that was part of the D.C. Superior Court Drug Intervention Program. Similarly, in an evaluation the Multnomah County, Oregon, S.T.O.P. (Sanction Treatment Opportunity Progress) Drug Court Diversion Program, Finigan (1998) estimated a benefit-cost ratio of 2.5 from the taxpayer perspective. In these studies, benefits were calculated as the dollar value of averted crime costs (Harrell et al.) or averted CJS [criminal justice system] costs (Finigan) due to decreased criminal activity."
Zarkin, Gary A., Laura J. Dunlap, Steven Belenko & Paul A. Dynia, "A Benefit-Cost Analysis of the Kings County District Attorney's Office Drug Treatment Alternative to Prison (DTAP) Program," Justice Research and Policy, Vol. 7, No. 1 (Washington, DC: Justice Research and Statistics Association, 2005), p. 3.