This chapter assesses the evidence for comparing the service delivered by publicly and privately run prisons.

Methodological and data issues

The difficulties of measuring prison performance have been considered at length, notably in Logan (1992), Gaes et al (2004) and Liebling (2010).

Logan proposes a list of aspects of what constitutes ‘good’ performance in a prison – keeping prisoners securely, in decent conditions, preventing them from harming themselves or each other, preserving them in good health, keeping them occupied, encouraging them to reform and helping them prepare for a law abiding and self-reliant life on release. In my experience, Logan's list, or something much like it, measures up pretty well against what politicians, prison managers and the public think a good prison should be and do. Of course, there is much less agreement on how to weigh these aims against each other, and how to resolve conflicts between them; while there are many different ways to measure performance against these aims, individually less than ideal, and together less than comprehensive.

Liebling (2010) argues that a list like Logan's does not get to the root of what constitutes really ‘good’ (or ‘poor’) performance in prison, and has pioneered another way of examining, and measuring, the culture of individual prisons, based on observation of prisoner and staff attitudes, behaviour, experience and perceptions. It may well be that both concepts of ‘performance’ have their place, for different purposes.

In any case, theoretical argument about what might be the best possible way of measuring performance, and why existing data all fall short in some way, is not the issue here. Rather, how much weight can be given to the evidence which we already have. This chapter consider seven sorts of evidence:

• 1. a series of studies by the Home Office on data from 1994– 95 to 1998–99, limited to ‘management only’ contracts (thus excluding PFI prisons);

• 2. a National Audit Office study, focusing mainly on PFI prisons;

• 3. the ratings for individual prisons inspected by HM Inspectorate of Prisons (HMIP) from 2005–06 onwards;

• 4. a statistical analysis of factors predictive of good Inspectorate ratings, conducted in 2009;

• 5. the Prison Rating System developed by NOMS, from 2008–09 onwards;

• 6. research comparing the culture of publicly and privately run prisons; and

• 7. statistical analysis of measures of quality in male local prisons.