A national crime trends expert, however, disagrees with the conventional wisdom that a soft economy prompts robberies. Andrew Karmen, a criminologist and professor at the John Jay College of Criminal Justice in New York, said crime does not rise and fall with the economy.

Instead, Karmen said, crime is driven by chronic problems facing people with poor education and limited job prospects even in the best of times. He says hiring more cops and building more prisons are expensive, temporary solutions that do not get at the root of the problem.

“My answer is, we tackle the social roots of crime that are clearly linked to unemployment, lousy schools and limited opportunities,” he said.