Inmates in private prisons spend more time behind bars than those in public prisons and are just as likely to commit crimes after their release, a UW study found.
In what may be the first study of its kind, Anita Mukherjee, an assistant professor at the University of Wisconsin-Madison School of Business, compared average time served and recidivism at public and private prisons. She found that the lower costs that make private prisons attractive are undermined by longer stays.
And while the private prison industry often claims that innovative rehabilitation programs lead to better outcomes, she found that inmates coming out of private prisons are just as likely to commit new crimes.
The study does not apply to the prison system in Wisconsin, where inmates are housed in publicly owned facilities operated by public employees. But in the U.S., the $5 billion private prison industry houses 10 percent of the nation's inmates.
"There is a basic fairness issue here," Mukerjee said Wednesday in a press release announcing her findings. "Should prisoners be serving more time simply because they were randomly assigned to a private prison instead of a public one?"
Mukherjee came up with her findings by studying data between 1996 and 2004 from prisons in Mississippi, where private prisons house 40 percent of the state's inmates. She found that inmate stays in private prisons were 4 to 6 percent longer than in public prisons, which came to 60 to 90 days for the average inmate.
"The number of days a prisoner serves relates directly to the cost of housing that inmate," she said. "So if inmates sent to private prisons somehow serve longer terms, this undermines the very cost benefit that makes private prisons attractive relative to public prisons."
The longer prison stays were the result of sanctions for prison violations, which were applied more often in private settings regardless of demographic, offense or sentence length.
"The findings suggest that states hiring private prison contractors need to exercise care in structuring incentives that match their desired public policy outcomes, whether it be reducing costs or reducing recidivism rates," said Mukherjee. "States may want to consider increased monitoring to prevent excessive violations to keep costs in line or having contracts that don't just reward operators for filling beds but require them to produce outcomes such as reduced rates of recidivism."