ONE of the happy trends of 2009 has been that crime is down in major American cities, even the ones that have had a rough year in other respects. Today the New York Timesreports that New York City is on track to have its smallest number of murders since 1962:

There were days upon days in New York City when not a single person was murdered in 2009. Two such stretches, in February and March, lasted nearly a week each.

The trend can be understood as crime being on a downward trajectory for years, for a variety of reasons—the end of the crack epidemic, better gun control, new policing strategies, and so on—rather than something special about 2009. But the concurrence unsettles the widespread and intuitive belief that violent crime will rise during times of economic distress. Perhaps property crime, theft and the like, has more reason to spike during a downturn? Here in Austin, a memorable crime of the year was that someone punched a hole through the wall of a popular Mexican restaurant and stole a bag of meat. But property crime, according to the FBI's preliminary statistics, is also in decline.

This is worth keeping in mind as concerns about public safety and police staffing will come up often during next year's elections. And there is no reason to feel complacent. Earlier this year one criminologist fretted to me that although he wasn't seeing a direct relationship between crime and the downturn at the moment, he would look for a spike in a few years, from young people who had been derailed from entering the workforce.

The Los Angeles Times, observing a similar downward trend in southern California, suggests that expectations matter:

Southern California's widespread decline in crime may be due in part to the example set by the LAPD's long-running success under Beck's predecessor, Chief William J. Bratton, said George Kelling, a leading criminal justice scholar at Rutgers University. "Where police chiefs might have been perfectly willing to say, 'It's the economy or something else and there's nothing we can do about it,' their bosses—mayors and city councils—now know they can and should expect reductions in crime," Kelling said. "There is now a pressure of, 'If you can't get the job done, we'll find someone who can.'"

(Chart credit: New York Times)