Underreporting of Substance Use in a National Longitudinal Youth Cohort: Individual and Interviewer Effects

Abstract

The quality of drug data in the 1984 wave of the National Longitudinal Survey of Youth is explored. Comparisons with other national surveys indicate that underreporting of use of illicit drugs other than marijuana appears to have taken place, and that light users of these drugs are underrepresented among the self-acknowledged users. Comparison with marijuana use reported four years earlier indicates that experimental marijuana users are much less likely than extensive users to acknowledge involvement. Even after controlling for frequency of use, underreporting is more common among terminal high school dropouts and minorities. Not only individual characteristics but field conditions also contribute to underreporting. Familiarity with the interviewer, as measured by number of prior interviewing contacts, depresses drug use reporting. We speculate that interviewer familiarity increases salience of normative standards and that participants respond not only in terms of their past familiarity but also in terms of their subjective expectations regarding the probability of a future encounter with the interviewer