Key longitudinal-experimental studies in criminology

Following the tradition of Joan McCord's work, this paper reviews longitudinal-experimental studies in criminology with community samples of at least 100 persons, follow-up periods of at least 5 years, personal interviews, and measures of offending. The main advantages of such studies are in investigating both the natural history of development (including the effects of risk/protective factors and life events) and the impact of interventions on offending. This paper also reviews advantages and problems of prospective longitudinal surveys, randomized experiments, and longitudinal-experimental studies in criminology. Four key longitudinal-experimental studies were conducted by Joan McCord, Richard Tremblay, Lawrence Schweinhart and David Olds. Other studies have been conducted, or are currently under way, but no criminological study has yet been published with several years of personal data on participants both before and after an intervention.Joan McCord Award Lecture given at the American Society of Criminology, Toronto, Canada.