Applications of operant techniques in treatment and education have proliferated in recent years. Among the various techniques, the token economy has been particu- larly popular. The token economy has been extended to many populations included in psychiatry, clinical psychology, education, and the mental health fields in general. Of course, merely because a technique is applied widely does not neces- sarily argue for its efficacy. Yet, the token economy has been extensively re- searched. The main purpose of this book is to review, elaborate, and evaluate critically research bearing on the...