ABSTRACT
Research presented in this article addresses some of the competing claims about the value of prospective longitudinal self-report data for studying the relationship between age and crime. More specifically, the debate over the magnitude of potential testing effects in longitudinal data is assessed by analyzing involvement in delinquency, serious offending, and victimization using self-report data from the first five waves of the National Youth Survey. The results of growth curve analyses suggest that panel and maturation effects warrant serious concern in longitudinal studies that rely on self-report information. The analyses show that regardless of the subject’s age at the start of data collection, average self-reported involvement in crime declined substantially over time. Data from external sources suggest that period effects are not responsible for this decline. Furthermore, while traditional measures of delinquency are reliable for studying between- individual differences in crime, these same measures may lack the reliability necessary for studying between-individual differences in changes in crime over time.
