Earlier this year the Arizona Department of Corrections (ADC) released a provocative, but flawed study claiming that per capita prisoner costs in Arizona's private prisons are higher than state-run prisons. However, there were a number of methodological problems with this widely-cited study that led to inaccurate public-private cost comparisons.
Unfortunately, the Arizona's Auditor General relied on the flawed ADC study in its recent performance audit of the department. The audit admittedly "did not assess the (ADC's) method for adjusting the per capita rates for comparing state-operated and private prison costs."
But that hasn't stopped the media from reporting it. Just yesterday, the Auditor General's review was cited by Arizona CBS affiliate KPHO in a report entitled, "Audit: Private Prisons Cost Slightly More." A spokesperson for Gov. Jan Brewer responded to the KPHO story saying the governor has commissioned another prison cost-comparison study.
The governor's office should be commended for taking a closer look at this data, because it seems to have skewed the dialogue on privatization of correctional facilities in that state. Earlier today I posted a commentary on Reason.org detailing the mistakes made in the ADC's original study -- that commentary is available here.