Pro Bono Economics worked with Revolving Doors to review the feasibility of completing an economic analysis of the costs and benefits of adopting diversion policies – a range of approaches intended to redirect individuals away from imprisonment and criminalisation and towards rehabilitation and support.

The criminal justice system in England and Wales creates a vicious cycle of offending and reoffending that imposes huge costs on society. More than half of all adults that receive a custodial sentence of less than 12 months go on to reoffend within a year of release, with an individual’s previous offending history acting as the single most important predictor of an individual’s likelihood of reoffending. The cost of this reoffending cycle is estimated at over £18 billion each year.

Revolving Doors is a national charity that champions long-term solutions for justice reform that tackle the root causes of reoffending and support people’s journeys towards better lives. Revolving Doors focuses on the ‘revolving door’ group of people, those who have repeat contact with the criminal justice system for low level offences, whose behaviours are largely driven by unmet health and social needs, such as mental ill health and homelessness.

We reviewed existing evidence on the impacts of diversion to establish whether it would be feasible to assess the economic cost and benefits of diversion policies. We found that, despite the emerging evidence base, there is not sufficient evidence to support the development of a robust economic case for diversion policies in the UK at this time. While much of the evidence is at least suggestive that diversion approaches are beneficial, there is a need to further invest in robust, larger-scale research and evaluation studies to provide a clearer definition and categorisation of diversion policies, show the impact of different types of diversion policies in the UK, and quantify the costs of introducing these schemes in practice.

We would like to thank Helen Hughson, Rachael Hunter and Callum Bridge-Adams for their support in delivering this project.