The World Prison Brief from King’s College London was released yesterday (you can read about Scotland’s prison stats here) and was the subject of much discussion in the news.

As report cards go, it didn’t make happy reading, according to the commentators. Our official incarceration levels have now overtaken even Turkey, to put us at the top of the Western European league table for banging people up (at last, something we excel at!). Actually Spain and Jersey lock up more people, but most of those are foreigners. Scotland leads the way in locking its own citizens away.

All of the commentary I have seen (e.g. this article in the Scotsman) decries this as bad news. An “international embarrassment” even. Rising numbers in prison, despite falling crime rates.

Okay, just pause a minute and consider that last sentence. Rising prison numbers, despite falling crime rates. Of course, there is another way of looking at those same facts. How about: crime rates falling as a result of rising prison numbers?

Maybe, just maybe, locking more people up prevents more crime? If you are in jail, you cannot commit more crime – and perhaps you being behind bars deters your friends and neighbours from following your path into a life of crime.

If so, the current ideas to stop putting people in jail and let them do community based disposals instead seems like a risky move. And I’m not just blindly speculating – a bit of careful internet-based research led me to an academic paper: “The Effect of Prison Population Size on Crime Rates: Evidence from Prison Overcrowding Litigation” by Steven D. Levitt of Freakonomics fame.

It’s a little bit wordy and complex, but as far as I can work out the conclusions are as follows:

• increased prison populations appear to substantially reduce crime;
• the marginal costs of incarceration are at or below the accompanying social benefits of crime reduction;
• incarcerating one additional prisoner reduces the number of crimes by approximately fifteen per year.

The paper also suggests that, where feasible, rehabilitation or prevention are preferable to imprisonment (both from a cost-benefit and humanitarian point of view) but it is concerning that the policy debate in Scotland begins from a standpoint that prison “isn’t working” when a proper consideration indicates that (at least in terms of crime reduction) it is probably working very well indeed, thanks very much.

Posted on Absolvitor: Scots Law Online.