A study carried out by research group Civitas shows that peaks in crime rates tend to be associated with a significant reduction in the prison population. Although this trend can be observed in several countries, for instance Denmark and Portugal, the paradigm example is Italy. In 2007, the total number of police recorded offenses catapulted by over 160,000, following a mass pardon of prisoners the previous year. The crime rate only began to fall once the prison population crept up towards its 2006 level.
It was the same story in Canada, where a sudden drop in the number of inmates from 2000 saw more crime in society. The opposite has happened in the Netherlands, where much tougher jail sentences appear to have driven down crime. The renowned American academic Steven Levitt argues ‘the evidence linking an increase in punishment to lower crime is very strong’.