Formal System Processing of Juveniles: Effects on Delinquency compares the crime-deterrent effectiveness when young offenders were processed through the official juvenile justice system or dealt with in an alternative way.

Based on a systematic review of the best existing evidence, the authors of this 2010 Campbell Collaboration report compared the crime-deterrent effectiveness of different paths by drawing on study data in which young offenders were randomly assigned to be processed through the official juvenile justice system or, instead, to be dealt with in an alternative way—either released outright or assigned to a formal diversion program.

Drawn from 29 randomized experiments involving 7,304 low-level juvenile offenders (age 17 or younger) from 1973 through 2008, the data show that the young people who went through the system were more likely to commit subsequent crimes than those assigned to a diversion program with services.

Even those who were released outright were slightly less likely to commit subsequent offenses than those who had been assigned to the formal system—and that deterrent effect was achieved without the substantial costs of running young people through the formal system.