A few decades of comparative studies of public vs. private prison performance have failed to give a strong edge to either sector in terms of quality. That supposed market incentives haven't delivered spectacular results is unsurprising, since, by and large, market incentives haven't been allowed to work: outcomes are rarely measured and are even more rarely made the basis of compensation, and prison providers are rarely given substantial flexibility to experiment with alternative models.
Prison Accountability and Performance Measures,
Emory L. J.
Available at: https://scholarlycommons.law.emory.edu/elj/vol63/iss2/4