The study, done by Filipe Campante of Harvard’s Kennedy School of Government and Quoc-Anh Do of Singapore Management University, used a sophisticated statistical model to determine which capitals are the most isolated from their states’ population centers. They compared that measure of isolation with a database of convictions on federal corruption charges between 1976 and 2002. The results showed that the "more isolated capital cities are associated with more corruption." Further, "the overall level of education in a state appears to play a role," with less educated states tending toward more corruption.
The researchers looked for reasons. One possibility was that newspapers, which provide most coverage of state governments, are increasingly less likely to cover the capital, especially as its distance from their circulation area increases. In examining 436 U.S. newspapers, searching for references to state government, the study found “in states where the population is more concentrated around the capital, more intense media coverage of state politics, and therefore greater accountability.” In the past decade, the number of reporters covering state capitals has dropped sharply – a reduction of more than 30 percent between 2003 and 2009, according to the American Journalism Review.