While crime rates are going up in the US, in three major cities: NYC, Chicago and LA, it is going in the opposite direction. While innovate police work usually gets the credit, there is a demographic shift that is helping as well.
The most obvious change is that, thanks in part to high property prices, all three cities are shedding young people. Together they lost more than 200,000 15-to 24-year-olds between 2000 and 2005. That bodes ill for their creativity and future competitiveness, but it is good news for the police. Young people are not just more likely to commit crimes. Thanks to their habit of walking around at night and their taste for portable electronic gizmos, they are also more likely to become its targets.I would be curious to know what percentage of the decrease in crime can be attributable to these changes.
Another change is that poor Americans have been displaced by poor immigrants—who, as studies have repeatedly shown, are much better behaved than natives of similar means. This trend is symbolised by the disappearance of blacks. Roughly half of America's murder victims and about the same proportion of suspected murderers are black. In five years America's three biggest cities lost almost a tenth of their black residents, while elsewhere in America their numbers held steady.
via The Economist