The Economics Graduate Student Who Slaughtered The Elites

Not that hard to do when economists base their opinions on ideology rather than data:

Herndon became instantly famous in nerdy economics circles this week as the lead author of a recent paper, "Does High Public Debt Consistently Stifle Economic Growth? A Critique of Reinhart and Rogoff," that took aim at a massively influential study by two Harvard professors named Carmen Reinhart and Kenneth Rogoff. Herndon found some hidden errors in Reinhart and Rogoff's data set, then calmly took the entire study out back and slaughtered it.

...Herndon, who did his undergraduate study at Evergreen State College, first started looking into Reinhart and Rogoff's work as part of an assignment for an econometrics course that involved replicating the data work behind a well-known study. Herndon chose Reinhart and Rogoff's 2010 paper, "Growth in a Time of Debt," in part, because it has been one of the most politically influential economic papers of the last decade. It claims, among other things, that countries whose debt exceeds 90 percent of their annual GDP experience slower growth than countries with lower debt loads — a figure that has been cited by people like Paul Ryan and Tim Geithner to justify slashing government spending and implementing other austerity measures on struggling economies.

Before he turned in his report, Herndon repeatedly e-mailed Reinhart and Rogoff to get their data set, so he could compare it to his own work. But because he was a lowly graduate student asking favors of some of the most respected economists in the world, he got no reply, until one afternoon, when he was sitting on his girlfriend's couch.

"I checked my e-mail, and saw that I had received a reply from Carmen Reinhart," he says. "She said she didn't have time to look into my query, but that here was the data, and I should feel free to publish whatever results I found."

Herndon pulled up an Excel spreadsheet containing Reinhart's data and quickly spotted something that looked odd.


"I clicked on cell L51, and saw that they had only averaged rows 30 through 44, instead of rows 30 through 49."

What Herndon had discovered was that by making a sloppy computing error, Reinhart and Rogoff had forgotten to include a critical piece of data about countries with high debt-to-GDP ratios that would have affected their overall calculations. They had also excluded data from Canada, New Zealand, and Australia — all countries that experienced solid growth during periods of high debt and would thus undercut their thesis that high debt forestalls growth.

...When Herndon and his professors published their study, the reaction was nearly immediate. After Konczal's blog post went viral, Reinhart and Rogoff — who got a fawning New York Times profile when their book was released — were forced to admit their embarrassing error (although they still defended the basic findings of their survey). And today, another UMass Amherst professor, Arindrajit Dube, followed up on Herndon's paper with additional proof that there were serious theoretical and causal problems (as opposed to just sloppy Excel work) in the Reinhart-Rogoff study. Observers have been raising serious questions about what Herndon's work means for the future of austerity politics, and Reinhart and Rogoff's respectability as scholars.

...But Herndon's finding won't likely stop politicians from trying to reduce the deficit. The global march for austerity began before Reinhart and Rogoff's work was published, and will continue as long as there are people who believe that governments can shrink their way to prosperity