The FBI recently announced that the number of violent crimes fell 5.5 percent in 2010, with property crimes falling 2.8 percent. This extends the dramatic reduction in crime that began in the 1990s. The Times declared that criminologists were baffled by the news, and Levitt was baffled by their bafflement:
Apparently, everyone expected crime to rise because of the weak economy, which I find strange, because there is zero evidence of any relationship between violent crime and the economy, and a relatively weak one between property crime and the economy. Plus, relative to 2009, the economy in 2010 was substantially improved.
We spent an entire chapter in Freakonomics exploring the factors that do and do not seem to have brought down the rate of violent crime in the U.S. In short, factors that matter include: number of police; number of prisoners; changes in drug markets; and the availability of abortion. And those that don't seem to much matter: the economy; innovative policing strategies; most gun laws; capital punishment; and demographics.
There is of course no reason for anyone to have complete confidence in the arguments we presented, even if they were more empirical than most arguments about crime. Still, as Levitt said in the excerpt above, it is surprising that so many people seem wedded to the view that the economy drives violent crime even when the evidence supports the contrary.
So, given the amount of bafflement on the issue, it seemed like a good time to convene a Freakonomics Quorum.