But elected officials, and their constituents, want concrete evidence of what is essentially a shadowy illegal activity. Wild Guesses Left unchallenged, even the wildest guesses take on the certitude of fact. In 1978, Congress created the National Narcotics Intelligence Consumers Committee as a repository for drug statistics. The committee led to what Mark A. R. Kleiman, a drug policy expert at the University of California at Los Angeles, calls ''estimation by negotiation,'' as intelligence officials sat down to debate what the official numbers should be. Such numbers are irrelevant anyway, says Peter Reuter, a drug policy specialist at the University of Maryland, because they play virtually no role in shaping the nation's drug policies.
Wild figures distract attention from the true nature of the problem.
Last December alarms went off about rampant drug use among American youth after an annual survey by the University of Michigan reported that half of high school seniors said they had tried drugs, up 20 percent from 1992. The survey indicated the experimenting mostly involved marijuana. In other words, most teen-agers are not abusing hard drugs. The latest estimate of 12.8 million drug users in this country is little more than half of the 25 million users reported in 1979. But what worries researchers like Lloyd D. Johnston, the author of the survey, is that more kids are trying marijuana at a younger age, which may put them at risk for harder drugs.