Social scientists who study corruption have long debated the relative importance of legal incentives and cultural norms (“people like us don’t do that”) in the decision to act for or against the public good. Many economists lean toward the view that most people will act similarly, given similar incentives, and that cultural norms are less important.

In an ingenious study published in June, however, the Columbia University economist Raymond Fisman and Edward Miguel of the University of California at Berkeley argued that culture plays a powerful role. The two scholars studied parking tickets that were racked up in Manhattan by diplomats from 146 countries who were posted to the United Nations. In a situation in which every diplomat essentially received an invitation to be corrupt, diplomats from nations with “clean” governments said, “No, thanks.”

The study began with the observation that, until late 2002, there was essentially zero enforcement of parking rules where diplomats were concerned. Diplomats were ticketed, but few if any cars were towed, and no one demanded payment. Using public records stretching back to 1997, Fisman and Miguel identified which diplomats had delinquent tickets, and how many — 150,000 in all, representing more than $18 million in fines.

If incentives trumped culture, you would suppose that diplomats from every nation would cheat. But in fact, attachés from Canada, Ireland, Scandinavian nations and Japan evidently drove around the block till they found a spot. (Diplomats with few or no unpaid tickets also tended to get few tickets, period.) The worst offenders, meanwhile, came from Kuwait (246 unpaid tickets per diplomat), Egypt, Chad, Sudan, Bulgaria, Mozambique, Albania, Angola and Senegal. This behavior correlated strongly with the scores of diplomats’ home countries on a measure of public corruption compiled by World Bank researchers.