Fascinating stuff this, like a press release from the Howard League on how we should treat criminals.

I'm sitting in Oslo having lunch with the director general of the Norwegian prison service – Kristin Bolgen Bronebakk – and we are discussing "Scandinavian exceptionalism". In other words, why is it that Finland, Sweden and Norway in particular, have much lower rates of imprisonment than other European countries?

Isn't that wonderful? They've managed to design a system where those who employ their rapacity upon their fellow citizens do not end up warehoused, locked in a cell for 23 hours a day, in a Victorian building. Perhaps there's something we might learn from this system, how do they do it?

Oslo had the highest rate per person in Scandinavia in terms of reported crimes, with 90 reported crimes per 1,000.

Copenhagen had 50 crimes reported per 1,000 and Stockholm had 79.

In New York, there were 22 reported crimes per 1,000 inhabitants.

As economists have endlessly pointed out, it's not just punishment for crime that reduces crime. It's a combination of the severity of the sentence, the conditions of serving it plus the liklihood of detection and conviction. All those together add up to the expected punishment for a particular action.

And whatever else the Norwegian version of social democracy might have to tell us here it seems clear that not locking up criminals does not reduce crime.

So that's one more thing that we know not to do then.