A University of Strathclyde economist tracking tens of thousands of offenders through England and Wales's criminal justice system has found something that defies the easy cynicism often surrounding prison reform: supervision works, at least for first-time offenders. The research by Dr. Markus Gehrsitz and his team at the Fraser of Allander Institute reveals that people released from prison are significantly less likely to reoffend when subject to supervision and license conditions—cutting reoffending by 15% in the crucial first four weeks after release, and by 5.5% over the following three years.
This matters because it challenges a widespread assumption that monitoring and control cannot genuinely reshape behavior. The study found that supervision and license conditions—which require good behavior, a fixed residence, and regular contact with a probation officer—now apply to all individuals released from prison in England and Wales. Yet despite these universal requirements, reoffending rates remain stubbornly high, with more than half of adults released from sentences of less than one year reconvicted within a year. Understanding what actually works becomes crucial.
The researchers drew on anonymized administrative data from the Ministry of Justice's Data First Cross-Justice Datasets, following individuals through prisons, courts, and probation systems. The initial 15% reduction in the first four weeks partly reflects prison recalls—14-day returns to custody issued by probation officers when license conditions are breached. These temporary incarcerations suppress offending by returning individuals to custody. But the enduring 5.5% reduction over three years tells a different story. Because probation officers can only issue recalls in the initial months following release, the longer-term gains reflect genuine behavioral change, not merely mechanical suppression.
The picture is more nuanced when examined by offender history. While supervision dramatically helps first-time prisoners, those with five or more previous prison spells show little behavioral change from supervision alone. Similarly, intensive supervision proves more effective for those released from longer sentences. Offenders who served six to twelve months had markedly lower reoffending rates than those released after two months or less, largely due to longer and more intensive license periods.
The study found that the policy reduced theft and other non-custodial offenses most effectively, and also led to fewer violent crimes—though this effect dissipated over time, with researchers unable to rule out "zero" effect after one year. Supervision's effectiveness did not vary by gender, ethnicity, or age.
Perhaps most striking for policymakers: the economic case is clear. Every additional pound spent on supervision avoids more than £2 in crime-related costs, including policing, court time, and victimization. Yet the researchers emphasize that supervision is no panacea. In their data, around two-thirds of people released from short sentences reoffended within one year. Offender supervision mitigates the problem but cannot solve it alone.
Dr. Gehrsitz noted that the research "shows the potential of large administrative datasets to evaluate policies affecting hundreds of thousands of people." The project's legacy extends beyond its findings: the code used to generate the datasets will be made available to other researchers, potentially opening new avenues for understanding what works in criminal justice reform.