Collective Action: Getting the Lead Out
Crime guru James Q. Wilson surveys the evidence for why violent crime rates have dropped so dramatically over the past two decades. The state of the economy, he says, seems to have little to do with it:
The biggest effect seems to be due to getting rid of lead based paints, so that kids have less lead in their developing brains. Bottom line:
So if I can put words into Wilson's mouth, the decline in crime is perhaps one-quarter due to increased incarceration, one-quarter due to reduced cocaine use, and one half due to reductions in blood lead levels in children.
Note that getting rid of lead based paints and reducing cocaine use are both the kinds of actions libertarians abhor.