Abstract
▪ Abstract The United States in the 1990s has experienced the greatest sustained decline in violent crime rates since World War II—even though rates thus far have not fallen as rapidly as they increased during the crime boom of the 1960s and early 1970s. I review a set of exogenous and policy-related explanations for the earlier crime boom and for the crime bust of the 1990s. I argue that our understanding of crime trends is hampered by a lack of longitudinal analysis and by ahistorical approaches. I identify a set of questions, concepts, and research opportunities raised by taking a more comprehensive look at crime waves.