CHICAGO (CBS) — A former Chicago alderman turned political science professor/corruption fighter has found that Chicago is the most corrupt city in the country.

He cites data from the U.S. Department of Justice to prove his case. And, he says, Illinois is third-most corrupt state in the country.

University of Illinois at Chicago professor Dick Simpson, who served as alderman of the 44th Ward in Lakeview from 1971 to 1979, estimates the cost of corruption at $500 million.