Research Brief

Headlines about falling crime rates notwithstanding, this year there will still be one violent crime committed for every 130 U.S. citizens—a rate several times that in other industrialized democracies. Yet despite the seriousness of America's crime problem, most of the money and effort devoted to solving it are restricted to one approach—incarcerating persons who have already committed crimes. Much less attention has been paid to diverting youths who have not yet committed crimes from doing so.

This lopsided allocation of resources is in part quite rational. When a criminal is imprisoned, there is little doubt that crimes are being prevented by that person's incapacitation. However, programs aiming to reduce the flow of children into criminal careers are not so easily evaluated. Children who will wind up in trouble with the law cannot be identified with certainty, program participation cannot ensure against eventual criminal activity, and any positive effects can wear off. Still, some benefit from such programs should be realized. How much? And at what cost?

Peter Greenwood and his colleagues at RAND have made an initial attempt to answer these questions, and their findings suggest that some approaches to preventing criminal careers look promising enough to warrant more extensive demonstration.

Measuring Costs and Benefits

The RAND analysts considered four different approaches to intervening early in the lives of children at some risk of eventual trouble with the law. Risk of that kind is, of course, difficult to determine, but research shows that the children of young, single, poor mothers are at greater risk of engaging in criminal activity than are others. Some interventions might be targeted to such families, while others could be based on the child's behavior. The four approaches examined were as follows:

  • Home visits by child-care professionals beginning before birth and extending through the first two years of childhood, followed by four years of day care.
  • Training for parents and therapy for families with young children who have shown aggressive behavior in school.
  • Four years of cash and other incentives to induce disadvantaged high school students to graduate.
  • Monitoring and supervising high-school-age youths who have already exhibited delinquent behavior.

Each of these approaches has been attempted, and the top line of the table shows the efficacies of these pilot programs in terms of reductions in arrest or rearrest rates. These reductions are not likely to be as big once these programs are scaled up. Effects are also likely to decay with the passage of time, especially with respect to any effects on behavior beyond the juvenile years. In the second and third lines, the table shows hypothesized effective prevention rates taking into account these scale-up and decay penalties. Larger penalties were taken for the two earlier interventions, as their effects have more opportunity for decay before children reach a crime-prone age.

The table shows another factor influencing ultimate program benefit—the targeting ratio, or ratio of the expected lifetime crime rate for the group participating in the program to that for the population as a whole. Again, the later programs can be focused more narrowly on youths at greater risk of criminal activity. Finally, the table shows an estimate of the costs of each program per participant.

Program Effectiveness and Cost Parameters

Parameter Visits and Day Care Parent Training Graduation Incentives Delinquent Supervision
Pilot prevention rate (%) 50 60 70 10
Effective prevention rate for juvenile crime (%) 24 29 56 8
Effective prevention rate for adult crime (%) 9 11 50 8
Targeting ratio 2:1 2:1 3:1 4.5:1
Cost per participant (thousands of dollars) 29.4 3.0 12.5 10.0

Comparing Costs and Benefits

Cost-Effectiveness of Early Interventions, Compared with That of California's Three-Strikes Law

When combined with other information, the data in the table permit estimates of how many serious crimes would be averted over the lives of all program participants. These estimates can be expressed in terms of serious crimes prevented for every million dollars spent on each program. These are presented in the figure, along with a similar estimate for one high-profile incarceration program—California's "three-strikes" law extending sentences for repeat offenders. Three of the four early-intervention approaches compare favorably in cost-effectiveness with incarceration. Caution must be exercised, however, before taking these results at face value, for two reasons:

  • The costs of the four early interventions are based solely on the program costs shown in the table. They do not take into account the savings realized by not having to eventually imprison those youths diverted from criminal careers. Greenwood and his colleagues estimated that graduation incentives, for example, would save enough money to pay most of the program's costs.
  • Because the estimates shown in the table are the results of limited demonstrations and educated guesses, actual values could vary considerably from those shown. The researchers found, however, that substantial variations in the table values do not reverse the cost-effectiveness outcomes relative to the three-strikes law.

None of this suggests that incarceration is the wrong approach. If implemented at full scale, the early interventions' total impact on California's crime rate would be smaller than that of the three-strikes law. A previous analysis estimated that the three-strikes law might reduce serious crime by approximately 21 percent. Graduation incentives might bring about a reduction of 15 percent, the other interventions less.

The crime reductions achievable through three-strikes laws like California's are indeed substantial. But, with 80 percent of serious crime remaining, Americans will want to know what else can be done. This study indicates that crime could be reduced further through parent training, graduation incentives, and supervision of delinquents. Given California's vote in favor of the three-strikes law, the public may believe that a 21 percent reduction in crime is worth the measure's cost of $5.5 billion a year. For less than another billion dollars, graduation incentives and parent training could roughly double that crime reduction, if they are as effective as suggested here. To find out if they are would require broader demonstrations costing millions of dollars. The RAND team concluded that such demonstrations would be an investment worth the cost.

This report is part of the RAND Corporation research brief series. RAND research briefs present policy-oriented summaries of individual published, peer-reviewed documents or of a body of published work.

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.