A third decision, reflecting the committee’s charge, was to consider research that bears directly on drug policy, not basic research on drug addiction. Chapters 5 through 8 report the committee’s assessment of the research currently available to support analysis of drug control policy and make recommendations for improvements. Chapter 5 examines supply-reduction policy in totality, ranging from foreign interdiction to local policing strategies. Chapters 6, 7, and 8 examine the three main elements of demand-reduction policy: sanctions against use of illegal drugs (Chapter 6), drug education, persuasion, and other prevention activities (Chapter 7), and treatment of drug users (Chapter 8).

As the committee went about its work, it found very different modes of research in use to evaluate different instruments of drug control policy. At one extreme, establishment of the National Institute on Drug Abuse in the 1970s has fostered the development of a considerable body of research on drug treatment that has sought to adhere to the model of medical research. Here the units of analysis are individuals, and randomized clinical trials are considered to be the “gold standard.” Observational studies of samples of individuals receiving different treatments are viewed as expedients that may have to serve until randomized trials can be performed.

At another extreme, the few studies of foreign interdiction performed to date have employed either the observational approach of impulse-response analysis or the theory-oriented approach of systems research. These modes of research reflect the difficulty of the problem. The units of analysis for study of interdiction policy are large geographic regions within which the interactions of many distinct actors determine drug production and distribution. Moreover, interdiction studies have had to make do with hardly any data at all on the behavior of these agents. After all, it is very difficult to obtain evidence about illegal enterprises, especially those operating in foreign countries.

The committee does not see much prospect for convergence to a common mode of research on different aspects of drug control policy. Hence Chapters 5 through 8 vary considerably in the tenor of their discussions and in the foci of their recommendations. The committee acknowledges that the effectiveness of drug treatment, prevention, and law enforcement activities cannot be evaluated with equal ease or rigor. However, a common standard of proof can and should be applied to assess the credibility of all research aiming to inform policy. The strength of the policy conclusions drawn in a study should always be commensurate with the quality of the evidence. For a complete list of the committee’s recommendations, see Table 1.1 at the end of this chapter.