Claims that work release is cheaper than institutional care have the most substantial empirical support. Operating costs for work release are lower, although 'hidden costs' have not been adequately researched. Studies supporting work release as a factor in lower recidivism rates generally have the weakest designs and controls; criteria for client selection and failure/success and followup periods are poorly set. As an example, a study by Hoffman and Stone-Meirerhoffer (1980) obtained a range of recidivism rates from 8.7 to 60.5 percent by varying the sample criteria and the followup periods. Similarly flawed evaluations attempt to prove that work release helps maintain family unity, keeps down ex-offender unemployment, and boosts inmates' self-esteem. Results are mostly mixed, and relationships among variables unclear. Of the several explanations of the commitment to work release despite little evidence of its benefits, only one is truly satisfying. Work release programs satisfy competing correctional ideologies (custody and treatment) and maintain State control over persons who would otherwise probably be paroled. About 50 references are provided.