Abstract
Crime is a subject of intense emotions, conflicting ideologies. However, economists have generally explained it as a reflection of individual choice and equilibrating market forces. Two major themes of the literature are outlined: the evolution of a 'market model' to explain the diversity of crime across time and space, and the debate about the usefulness of 'positive' versus 'negative' incentives. Systematic analyses generally indicate that crime is affected on the margin by both positive and negative incentives; there are serious limitations to the effectiveness of incapacitation and rehabilitation; and optimal enforcement strategies involve trade-offs between narrow efficiency and equity considerations.