Available beds in any correctional facility have a tendency to become filled—no matter what the size of the facility. Jail crowding is a symptom of the policies and practices of the larger criminal justice system. The changes that have occurred in the nation’s jail population during the past 30 years provide evidence that policy shifts alone can bring about dramatic changes in the demand for jail beds. Furthermore, reductions in crime do not necessarily translate into reduced demand. There is no correlation between crime rates and incarceration rates. Instead, unstated, and often unexamined, policies across adjudication decision points in the criminal justice system largely drive jail bed usage.