The paper studied rehabilitation programs in 17 countries, and attempted to determine whether rehabilitation programs reduced recidivism and, if so, for which prisoners and under what circumstances. Treatment programs to enhance prisoners' socioeconomic capabilities include prison work and vocational training and education. Problems with work and vocational training include insufficiency of work, security concerns, and inadequate follow-up and evaluation. Problems in education efforts include difficulty in grouping prisoners to attend class, lack of qualified special teachers to carry out academic programs in prison, and poor learning environments. The paper suggested solutions and countermeasures to deal with the problems. It also described specific treatment programs for prisoners with psychological problems, drug addicted prisoners, sex offenders, violent offenders, and organized crime offenders. It described potential problem areas in each program and suggested methods individual countries had devised to deal with or prevent them. The paper discussed ways to recruit and retain staff qualified to administer rehabilitation programs. References, tables