Christian Henrichson and Ruth Delaney

Staff from Vera’s Center on Sentencing and Corrections and Cost-Benefit Analysis Unit developed a methodology to calculate the taxpayer cost of prisons, including costs outside states’ corrections budgets. Among the 40 states that participated in a survey, the cost of prisons was $39 billion in fiscal year 2010, $5.4 billion more than what their corrections budgets reflected. States’ costs outside their corrections departments ranged from less than 1 percent of total prison costs in Arizona to as much as 34 percent in Connecticut. The full report provides the taxpayer cost of incarcerating a sentenced adult offender to state prison in 40 states, presents the methodology, and concludes with recommendations about steps policy makers can take to safely rein in these costs. Fact sheets provide details about each of the states that participated in Vera’s survey.

Important note: When calculating savings (or costs) that result from reductions (or increases) in a state’s inmate population, do not use the per-inmate average costs in this report. Instead, use the marginal cost per inmate. The marginal cost is the amount that total correctional costs change when the inmate population changes. Using the average costs in this report to calculate savings or costs because of changes in the prison population will result in overestimates.

Please see A Guide to Calculating Justice-System Marginal Costs to learn more about these costs and how they are estimated.

For more information about cost analysis and other types of economic analysis of criminal justice policies and programs, visit cbkb.org, the website of Vera’s Cost-Benefit Knowledge Bank for Criminal Justice.