Microsoft Excel: The ruiner of global economies?
A paper used to justify austerity economics appears to contain an Excel error.
An economics paper claiming that high levels of national debt led to low or negative economic growth could turn out to be deeply flawed as a result of, among other things, an incorrect formula in an Excel spreadsheet. Microsoft's PowerPoint has been considered evil thanks to the proliferation of poorly presented data and dull slides that are created with it. Might Excel also deserve such hyperbolic censure?
The paper, Growth in a Time of Debt, was written by economists Carmen Reinhart and Kenneth Rogoff and published in 2010. Since publication, it has been cited abundantly by the world's press politicians, including one-time vice president nominee Paul Ryan (R-WI). The link it draws between high levels of debt and negative average economic growth has been used by right-leaning politicians to justify austerity budgets: slashing government expenditure and reducing budget deficits in a bid to curtail the growth of debt.
This link was always controversial, with many economists proposing that the correlation between high debt and low growth was just as likely to have a causal link in the other direction to that proposed by Reinhart and Rogoff: it's not that high debt causes low growth, but rather that low growth leads to high debt.
However, the underlying numbers and the existence of the correlation was broadly accepted, due in part to Reinhart and Rogoff's paper not including the source data they used to draw their inferences.
A new paper, however, suggests that the data itself is in error. Thomas Herndon, Michael Ash, and Robert Pollin of the University of Massachusetts, Amherst, tried to reproduce the Reinhart and Rogoff result with their own data, but they couldn't. So they asked for the original spreadsheets that Reinhart and Rogoff used to better understand what they were doing. Their results, published as "Does High Public Debt Consistently Stifle Economic Growth? A Critique of Reinhart and Rogoff," suggest that the pro-austerity paper was flawed. A comprehensive assessment of the new paper can be found at the Rortybomb economics blog.
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Sharp-eyed student takes on famed economists over basic errors - and wins
Edward Krudy
NEW YORK — *******
Published Thursday, Apr. 18 2013, 9:03 AM EDT
Last updated Thursday, Apr. 18 2013, 10:29 AM E
When Thomas Herndon, a student at the University of Massachusetts Amherst’s doctoral program in economics, spotted possible errors made by two eminent Harvard economists in an influential research paper, he called his girlfriend over for a second look. As they pored over the spreadsheets Herndon had requested from Harvard’s Carmen Reinhart and Kenneth Rogoff, which formed the basis for a widely quoted 2010 study, they spotted what they believed were glaring errors.
“I almost didn’t believe my eyes when I saw just the basic spreadsheet error,” said Herndon, 28. “I was like, am I just looking at this wrong? There has to be some other explanation. So I asked my girlfriend, ‘Am I seeing this wrong?’” His girlfriend, Kyla Walters, replied: “I don’t think so Thomas.”
In the world of economic luminaries, it doesn’t get much bigger than Reinhart and Rogoff, whose work has had enormous influence in one of the biggest economic policy debates of the age.
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