1. The size and character of the crime decline -- 2. The environment for optimism : crime trends and attitudes about the effectiveness of crime policies -- 3. The usual suspects : imprisonment, demography, and the economy -- 4. Progeny of the 1990s : three new explanations of decline -- 5. Which twin has the Toni? : some statistical lessons from Canada -- 6. New York City's natural experiment -- 7. What happens next? -- 8. Seven lessons from the 1990s -- App. 1. Crime and abortion policy in Europe, Canada, and Australia -- App. 2. Supplementary statistics on crime trends in Canada during the 1990s -- App. 3. Trends for the city of New York and the United States during the 1990s -- App. 4. Measuring the extent of decline in selected high-decline cities.