Gaes and his distinguished co-authors offer a comprehensive analysis of public vs. private management of prisons, a competition that originated with the introduction of private facilities into the criminal justice system in the 1980s. The authors measure prison performance with the technique of multi-level modeling for simultaneous measurement of the individual and the institution. Their work points the way to improved penal policy and accountability, and will be a valuable resource for public administrators, policy analysts, corrections personnel and criminologists.