Usually a suffering economy translates to higher crime rates. But, even as the economy stinks it up, crime has continued to improve, especially in black communities, which are more vulnerable to the economic climate writes Slate's James Verini. "Blacks in the U.S. are like the canary in the mine. Their crime rates go up faster during recessions, and go down faster in good times,” Gary LaFree, director of the Department of Criminal Justice and Criminology at the University of Maryland, tells Verini. So how to explain the trend? Criminologists think this counterintuitive trend has something to do with Obama. 

One unlikely explanation that is gaining credence among experts, including some of the biggest names in the field, is a phenomenon tentatively dubbed “the Obama Effect.” Simply put, it holds that the election of the first black president has provided such collective inspiration that it has changed the thinking or behavior of would-be or one-time criminals. The effect is not yet quantifiable, but some very numbers-driven researchers believe it may exist. 

The theory isn't settled -- and most of the stats are only from 2009 so any Obama Effect may have faded -- but Verini has a roundup of the academic debate.