Will private prisons improve the total prison system? Overarching the answer to this question is, as always in areas of penal policy, the attitude of governments. It has been seen that there is already some distinct ambivalence as to whether, for example, the UK government is prepared to let this happen. But subject to that caveat, the answer to this crucial question will be found first in the performance of private prisons and second in their impact upon the public sector component of the prison system. The quality of their own performance will in turn be affected by the efficacy of accountability mechanisms, the discussion of which will be drawn together in the final chapter. As to cross-sector impact, the threshold question is how receptive the public component will be to the changes and challenges posed by the private sector. The first issue, then, is to identify the barriers to change and thus to cross-fertilization that exist within the public prison system.