by Eli Epstein-Deutsch
Carmen Reinhart and Kenneth Rogoff’s famous ratio of 90% debt-to-GDP, above which countries allegedly begin to experience negative growth, has been cited widely as a justification for austerity by politicians from American Senators Paul Ryan and Tom Coburn to European Commisioner Olli Rehn. Thus the commentariat have lit up at the recent discovery by Robert Pollin, Michael Ash and Thomas Herndon that Reinhart and Rogoff’s 2010 paper Growth in a Time of Debt contained serious errors, including methodological problems and unwarranted omissions of key data. In their new paper, the University of Massachusetts economists challenge the original growth-rate at the 90% debt-level, which may have been over two percentage points too low: a notable difference. Pundits such as as Paul Krugman have seized on this rebuttal as fresh evidence for a long-standing suspicion that the 90% case was overstated (the correlation never proved the direction of causality, he points out). Defenders of Reinhart and Rogoff such as a Douglas Holtz-Eakin claim that nothing in the takedown really rocks their world (the idea seems to be that debt is intrinsically known to be bad anyway, like sin). With the political tensions over austerity ratcheted up of late, the debate is only likely to heat up from here.