The costs and benefits of criminal justice policies and activities affect everyone. Understanding what goes into the costs of operating jails, prisons, probation and parole, courts, law enforcement agencies, treatment programs, and other segments of the criminal justice system is important for taxpayers, politicians, practitioners, and society as a whole.
Any economic study of a justice-related investment needs to use the right cost information in its calculations. The type of cost used makes a difference in the accuracy of a study’s findings, as well as its relevance for policymaking, budgeting, and practice. Vera’s Cost-Benefit Knowledge Bank for Criminal Justice has published this guide to help technical users and general readers understand marginal cost—the amount of change in total cost when a unit of output changes.