UNDERREPORTING OF SUBSTANCE USE IN A NATIONAL LONGITUDINAL YOUTH COHORT: INDIVIDUAL AND INTERVIEWER EFFECTS

The quality of drug data in the 1984 wave of the National LongitudinalSurvey of Youth is explored. Comparisons with other nationalsurveys indicate that underreporting of use of illicit drugsother than marijuana appears to have taken place, and that lightusers of these drugs are underrepresented among the self-acknowledgedusers. Comparison with marijuana use reported four years earlierindicates that experimental marijuana users are much less likelythan extensive users to acknowledge involvement. Even aftercontrolling for frequency of use, underreporting is more commonamong terminal high school dropouts and minorities. Not onlyindividual characteristics but field conditions also contributeto underreporting. Familiarity with the interviewer, as measuredby number of prior interviewing contacts, depresses drug usereporting. We speculate that interviewer familiarity increasessalience of normative standards and that participants respondnot only in terms of their past familiarity but also in termsof their subjective expectations regarding the probability ofa future encounter with the interviewer.