The overall findings showed that harsher criminal justice sanctions had no deterrent effect on recidivism. On the contrary, punishment produced a slight (3%) increase in recidivism. These findings were consistent across subgroups of offenders (adult/youth, male/female, white/minority).
Compared to community sanctions, imprisonment was associated with an increase in recidivism. Further analysis of the incarceration studies found that longer sentences were associated with higher recidivism rates. Short sentences (less than six months) had no effect on recidivism but sentences of more than two years had an average increase in recidivism of seven per cent.
Intermediate sanctions demonstrated no relationship with recidivism. This category included studies of intensive supervision, fines, boot camps, electronic monitoring, scared straight, drug testing and restitution. Once again, no differential effects were found with respect to age group, gender and race.