UK Home Secretary John Reid is in deep trouble, trying to manage a criminal justice system that has filled prisons to overflowing. In his defence, Reid claims that "projecting the prison population is never an exact science". Perhaps he should visit the US state of Washington, which has been using scientific principles to try to avoid a similar crisis.
Washington may need three new prisons by 2030 if its jail population follows current trends. But with each prison costing $250 million to build and $45 million per year to run, are more jails the best option? To find out, politicians have turned to the Washington State Institute for Public Policy (WSIPP), which has embraced "evidence-based" criminal justice.
WSIPP's approach mirrors the "systematic reviews" that are helping to turn clinical medicine into a rigorous science. WSIPP has compiled studies on interventions to reduce crime, and then conducted statistical meta-analyses to see which have the biggest effects. It has also calculated the cost of each intervention, and their financial benefits in terms of reduced crime.
The conclusions are striking. Some interventions with young offenders are particularly effective: "multidimensional treatment foster care" (MTFC), in which juvenile offenders are placed with foster families and treated with behavioural therapy, reduces crime by an average of 22 per cent, giving a net benefit of almost $78,000 over 13 years, per offender treated. By contrast, there is no evidence that electronic tagging of adult offenders to offset jail time helps prevent crime.
Incarcerating more criminals does have a positive effect: WSIPP calculates that boosting the prison population by 10 per cent can cut crime by up to 4 per cent. However, it is expensive, and the returns diminish as more offenders are put inside. So WSIPP has put forward a portfolio of alternative policies designed to stabilise the state's prison population at current levels, including treatment for drug addicted prisoners and MTFC. This would leave Washington about $1.4 billion better off by 2030 compared with a business-as-usual approach, which would involve building new prisons.
WISPP's predictions depend on some assumptions about Washington's particular circumstances – such as the existing rate of incarceration, which is higher than in the UK, but lower than across the US as a whole – but could the same basic principles be applied elsewhere, including the UK? "The Washington study uses evidence to assert that reducing crime will reduce the numbers going into prison, but we believe the relationship is more complicated than this," a UK Home Office spokeswoman says. "We do commission our own studies to inform our policies."
Reid's critics argue that prison overcrowding is an outcome of changes in sentencing policy by a government determined to appear tough on crime. Maybe, but with prisons in England and Wales full to bursting, the UK needs solutions, not recriminations. Perhaps evidence-based criminal justice could save the day.
Written by Peter Aldhous, New Scientist San Francisco
"This article is posted on this site to give advance access to other authorised media who may wish to report on this story, or quote extracts as part of fair dealing with this copyrighted material. Full attribution is required, and if reporting online a link to www.newscientist.com is also required. This story posted here is the EXACT text used in New Scientist magazine, therefore advance permission is required before any and every reproduction of each article in full. Please contact claire.bowles@rbi.co.uk. Please note that all material is copyright of Reed Business Information Limited and we reserve the right to take such action as we consider appropriate to protect such copyright."
THIS ARTICLE APPEARS IN NEW SCIENTIST MAGAZINE ISSUE: 10 FEBRUARY 2007
EDITOR'S NOTE: PRIOR PERMISSION IS REQUIRED BEFORE ANY REPRODUCTION OF THIS STORY IN FULL
IF REPORTING ON THIS STORY, PLEASE MENTION NEW SCIENTIST AS THE SOURCE AND, IF REPORTING ONLINE, PLEASE CARRY A LINK TO: http://www.newscientist.com
UK CONTACT - Claire Bowles, New Scientist Press Office, London:
Tel: +44(0)20 7611 1210 or email claire.bowles@rbi.co.uk
US CONTACT – New Scientist Boston office:
Tel: +1 617 386 2190 or email kyre.austin@reedbusiness.com