In many urban areas across the United States, police departments, criminal courts, probation and parole offices are the agencies of government most familiar to residents. A recent study of New York City, for example, showed that three-quarters of 18 to 19 year-old black men are stopped by the police each year. On any given day, eleven percent of young black men are in jail or prison, and one third are living under some form of correctional supervision. The prevalence of prison terms, police encounters, and other contacts with criminal justice have grown at a breakneck pace. The incarceration rate in America more than quadrupled over the last four decades. Imprisonment went up when crime grew – but also went up when crime declined.