Il crimine usa è collassato negli anni 90. Perché. Due cause plausibili: più polizia e più carcere. Una causa controversa: legalizzazione aborto.
The Freakonomics argument starts off very much like the argument I make in The Tipping Point. The startling decline in crime in major American cities in the mid-1990’s is a mystery. No one predicted it. Everyone thought that high crime rates were a permanent feature of urban life. And the standard arguments to explain why crime falls don’t seem to work in this case. Levitt and Dubner go through all the usual explanations for crime decreases—a booming economy, decline in the crack trade, innovative policing strategies, tougher gun laws, aging of the population—and find only two that they think really matter. Putting more police on the street, they say, which happened in major cities all over the country in the early 1990’s, was a major factor. So were the soaring numbers of young men put away in prison in that same period. But neither of those two factors, they argue, are sufficient to explain the full magnitude of the crime drop. There has to be something else—and their candidate for the missing explanation is the legalization of abortion.