This counterintuitive trend has had criminologists scratching their heads for several years now. Various theories are being offered, including the simplest: There is little or no correlation between crime and the economy. From the New Republic:
Consider, after all, the two big crime epidemics in the twentieth century--the first took root in the late 1960s, during a period of healthy growth; the other came during the economic doldrums of the late '80s and early '90s. The only constant here, it seems, is that both outbreaks were fueled by a major expansion of drug markets: heroin in the 1970s, crack in the 1990s. (The current recession has seen a surge in demand for prescription drugs like Oxycontin or Xanax, but, for a variety of reasons, those illicit markets aren't associated with the same levels of violence.) Many conservatives like this storyline. Writing in the Wall Street Journal earlier this year, Heather MacDonald noted that the recession "has undercut one of the most destructive social theories that came out of the 1960s: the idea that the root cause of crime lies in income inequality and social injustice."
Texas State University's Marcus Felson says that crime should go down during bad economic times because most crime is opportunistic, and during a recession there's aren't that many opportunities.
Felson's broader argument is that subtle changes in our social and economic environments can actually have big effects on crime rates. If, say, GM suddenly invents a better lock for its cars, auto theft goes down. If a city enforces existing liquor laws at its five worst bars (so that they're not serving alcohol to people who are already intoxicated, for instance), violence drops. If people start trimming their hedges and watching out for their neighbors, burglaries dwindle. And the would-be criminals don't just go elsewhere for looting or pillaging--they give up, and the overall crime rate drops. These ideas aren't classically conservative ("lock 'em all up!") or liberal ("rehabilitate 'em and address root causes").
During a morning press conference, Mayor Villaraigosa was shamelessly touting the new L.A. crime numbers as somehow reflective of his commitment to policing - perhaps forgetting the fact that crime is down in most of the major cities. This guy is one piece of work.
*Reader offers more explanations for the drop in crime:
--More people are imprisoned in the United States and for longer terms than before. (Even though many of these people are in for non violent crimes or for drug offenses, at least some of the prisoners are people who if they had been given lighter sentences or released earlier would have committed more crimes)
-- By and large street criminals are not very bright. The ubiquity of video cameras and even phone cameras and the willingness of perpetrators to share their criminal exploits over social media, have all made it easier for the police to identify and arrest culprits.