Most people are instinctively supportive of using drug prevention programs to "save our kids" from addiction. Nevertheless, it is appropriate and sensible to ask whether these programs actually work. For many years, there was little solid evidence on the affirmative side. Over the past 15 years, however, compelling evidence from rigorously conducted evaluations has repeatedly shown that the better school drug prevention programs-although by no means all programs-yield tangible effects, often across a variety of drugs.

A few studies have adopted this sort of "benefit-cost" or "policy analytic" approach. Those studies tend to conclude that school drug prevention's effects are large enough to make the effort worthwhile. In other words, the dollar value of averted drug use exceeds the cost of running the drug prevention program. The general conclusion stemming from this finding is that drug prevention programs are a good investment and society is well advised to fund them.

The Office of National Drug Control Policy (ONDCP) construes drug prevention in school to be an integral part of its strategy to reduce the consumption of illicit substances, along with border interdiction, drug treatment, and domestic law enforcement. The ONDCP's goals include reducing juvenile smoking and drinking because they are illegal activities for youth and because they are significant risk factors in predicting subsequent use of marijuana and harder drugs.

Drug use generates social costs in terms of increased health care, lost productivity, and other costs. The social value or social benefit of a drug use prevention program includes the social costs that would have been incurred without the program. Estimating the social costs of drug use is thus an important part of estimating school drug prevention's social benefit. Prevention itself also has a social cost in terms of the resources used in administering the program.

Substance use has many ill effects on the lives of users and, through those users, on the lives of nonusers. Some of these effects are intangible and are difficult if not impossible to quantify. Some studies have attempted estimates of a wide range of social costs of drug use. These costs include health care expenditures for medical consequences and for alcohol and drug abuse services, productivity reduction associated with premature death and with crime victimization, other costs of crime, and costs of social-welfare administration.

Finally, drug prevention in school can bring benefits that are not related to or caused by reduced drug use, such as reduced criminal activity, reduced precocious sexual activity, increased school retention and graduation, and other such benefits.

Research done regarding program costs of drug prevention in school confirmed a basic finding of Caulkins et al. (1999). The budgetary costs (e.g., for program materials and teacher training) are very small compared with the non-budgetary costs, in particular the opportunity cost of using school time to teach prevention rather than conventional subjects. To those responsible for allocating school district resources, it is the budgetary costs that are relevant. However, because we are interested here in social benefits, we are also interested in social costs, and those costs are not restricted to budgetary costs. The true dominant cost to society of a youth's receiving school-based drug prevention is not just the purchase price of any workbooks or posters to implement the drug prevention curriculum, or even the costs required to train the teachers. Rather, it is the loss to society from that student spending less time learning (and the teacher spending less time teaching) other more-traditional subjects. This conflict is a microcosm of the much broader and intensely debated issue of whether school time should be spent providing various social services and life-skills training or whether schools should focus solely on academic basics.

Research shows that drug prevention in school is a good investment from the benefit-cost standpoint. The best estimate of social costs saved per prevention program participant greatly exceeds the program cost per participant.