Most public stadium cost figures are underestimated since economists and policymakers fail to take into account “maintenance expenses, capital improvements, municipal services, and the abatement of local property taxes,” according to Long. Returning to the Gillette Stadium, Massachusetts did agree to pay for updating surrounding infrastructure, and the other often-ignored costs listed by Long.

When these costs are included, the average public bill for each of the 121 professional sports stadiums in operation at the end of the 2010 season increases to $259 million—78 percent of total average costs. This means the total tab passed on to American taxpayers for the 121 stadiums was $31 billion.