analysis. Consequently, the committee formed a classified subcommittee to investigate this matter and, more generally, to explore whether access to classified data may be germane to the broader objectives of the committee. See the section "Selection of Interdiction Events" in Chapter 3 for discussion.

Although the RAND and IDA studies use different assumptions, data, and methods, the committee can and does apply the same broad criteria in assessing the two studies. Both studies use quantitative methods to draw conclusions from data and assumptions. In assessing each study, the committee evaluates the appropriateness of the data used, the plausibility of the assumptions imposed, and the logic of the methods by which data and assumptions are combined. In each case, the committee does not hold the study to a textbook standard of an ideal scientific analysis. The committee applied a necessarily looser and more pragmatic standard: Are the study's findings sufficiently credible that they should be given weight in the analysis and design of national drug control policy?

The committee is now moving forward on its broad study of data and research to inform drug control policy. The process of scrutinizing the specifics of the RAND and IDA studies has helped the committee to frame the general questions that it will now address. Looking ahead, the committee plans to evaluate the knowledge presently and potentially available about the effectiveness of drug treatment programs, the economics of drug markets (e.g., substitution effects), and the effects of domestic law enforcement activities on drug use. The committee also plans to assess the data presently and potentially available on drug production, use, and prices. The committee's final report will address the broad issue of how data and research can, in the future, serve the objective of informing drug control policy.