The latest Bradbury v. Zimbalist economist slap fight over Braves stadium, explained

If you’ve been waiting patiently for the next shoe to drop in the exciting economist war of words between Kennesaw State University’s J.C. Bradbury and Smith College’s Andrew Zimbalist over the economic impact or lack thereof of the new Atlanta Braves stadium, you will be happy to hear this news: Bradbury has fired back at Zimbalist’s Braves-commissioned trashing of his economic studies, and does not pull any punches. In a 64-page response — “I wish this reply were shorter, but its extensive length results from the magnitude of errors that I am forced to address,” Bradbury writes — he goes through Zimbalist’s criticisms and excoriates them in language that … okay, it’s not that spicy for normal human discourse, but for an academic paper it is fire. Some of the highlights, and my attempts to translate them into trash talk fit for a layperson:

• “Andrew Zimbalist’s review of my retrospective analysis is deficient to the point of negligence,” writes Bradbury, and furthermore “has violated the standard protocols of scholarly discourse.” Most of this, Bradbury writes, involves 1) making assumptions that benefit his client’s desired outcome — namely, that the Braves stadium isn’t actually a huge money pit for Cobb County taxpayers — and 2) consistently accusing Bradbury of failing to do things that he explicitly did in his original study.
• One case where Bradbury accuses Zimbalist of cherry-picking: Zimbalist cites two studies showing increased property values around new stadiums as examples of how “some sports facilities have produced salutary financial outcomes.” Except the co-author of those studies is West Virginia University’s Brad Humphreys — who happens to be a co-author with Bradbury on other work — and Humphreys himself has written that those two studies probably aren’t representative of any larger trends, but just indicate that for stadiums built in areas primed for redevelopment, property values then go up because they would have gone up anyway, duh. (This is a big part of Bradbury’s argument about the Braves deal: Property values went up in Cobb County after the stadium was built, but no more than they did in surrounding counties, so you can’t credit the stadium with being the cause.)
• There’s a long section about Zimbalist griping that Bradbury said it was “egregious,” “specious,” and “incomprehensible” for the Braves to assume that revenue from new hotel and business taxes imposed around the stadium should count as the result of the presence of the stadium. Bradbury writes that that assumption is too all those things, because slapping new taxes on all spending in a seven-square-mile area around the stadium and then calling the revenue “stadium-related” makes about as much sense as taxing blue cars and then declaring that because blue cars weren’t taxed before the stadium was built, the blue car tax money was generated by the Braves. For good measure, he then cites Zimbalist himself, in a 2013 essay, as noting that an increase in spending right around a stadium doesn’t necessarily mean an increase in overall spending, so you can’t count it as a net gain.
• Bradbury cites several instances where Zimbalist accuses Bradbury of not explaining his methodology, to which Bradbury responds by citing exactly where in his paper he explained his methodology, and notes that Zimbalist could have easily found this if he’d bothered to use the search function.

There’s much more, but most of Bradbury’s upshot comes down to: Bradbury looked for any evidence that the Braves’ new stadium has caused Cobb County’s financials to improve significantly relative to neighboring counties and found none; Zimbalist’s retort is well, but maybe that will change in the future, if these several unlikely things happen: