Viking Rampagers Not Good Law & Order Role Models.

why is it that Finland, Sweden and Norway in particular, have much lower rates of imprisonment than other European countries?

Don't know, probably because they are populated by earnest Nordic types who believe criminals need to be understood. I'm not sure why we should consider them to be role models in crime prevention though, Finland has the highest murder rate in Western Europe, Sweden has the most crimes per capita in Western Europe. Norway is arguably a low crime country but a one out of three success rate suggests that the Nordic model isn't better than the system we already have.