We synthesize 53 meta-analyses on the effectiveness of correctional treatment applied to a wide variety of offender groups delivered in either custodial or community-based settings. Those meta-analyses revealed positive overall effects on reoffending of correctional treatment delivered in both settings. However, the treatment setting is also associated with complex moderator effects that implicate a policy trade-off between prioritizing strong performance and consistent effects. With respect to effect size, for most groups, community-based correctional treatment is associated with statistically significant larger reductions in reoffending than treatments delivered in custodial settings. With respect to effect precision, custodial treatments report more consistent effects on reoffending than community-based treatments.
Johann Koehler is an Assistant Professor in the Department of Social Policy and Director of the Mannheim Centre of Criminology at the LSE.
Professor Friedrich Lösel, Ph.D., is an emeritus Professor at the Institute of Criminology (IoC), University of Cambridge and the Institute of Psychology (IoP) at the Friedrich-Alexander-University Erlangen-Nuremberg (FAU). He is still carrying out externally funded research projects as senior professor of psychology (FAU) or honorary research fellow (IoC).