Cultures of Corruption: Evidence from Diplomatic Parking Tickets, by Ray Fisman (Columbia) and Edward Miguel (Berkeley).
From the abstract:
"...we exploit a natural experiment, the stationing of thousands of diplomats from around the world in New York City. Diplomatic immunity means there was essentially zero legal enforcement of diplomatic parking violations, allowing us to examine the role of cultural norms alone. This generates a revealed preference measure of government officials' corruption based on real-world behavior taking place in the same setting. We find strong persistence in corruption norms: diplomats from high corruption countries (based on existing survey-based indices) have significantly more parking violations, and these differences persist over time."
As they say, read the paper. Andy Gelman has a nice little discussion of this over on his blog, too.