Does high government debt hurt economic growth? Consider this recent Bloomberg Businessweek report.

“Growth in a Time of Debt,”, a 2010 study by Harvard University economists Carmen Reinhart and Kenneth Rogoff, was the rare academic work that had a huge influence on Washington policymakers. It argued that high government debt is associated with slow economic growth and that growth is particularly weak when gross government debt exceeds 90 percent of gross domestic product, a threshold the U.S. had already crossed. With its illustrious authors, wide-ranging analysis, and portentous title echoing Gabriel García Márquez, the paper was praised by everyone from House Budget Chairman Paul Ryan to former Treasury Secretary Timothy Geithner. Alan Simpson and Erskine Bowles called on Reinhart to testify before their deficit reduction commission. Journalists cited the paper as the definitive word on growth and debt, while conservative lawmakers used it to justify cutting spending. …

… Now the notion that fighting debt is an urgent priority is further weakened by the authors’ acknowledgment that they made an error in a spreadsheet. Three economists at the University of Massachusetts at Amherst revealed the mistake on April 15.

The Excel mistake is more of a public-relations disaster than a significant slip. Reinhart and Rogoff wrote that average growth in high-debt countries was -0.1 percent. The UMass researchers said it was really 2.2 percent. But the spreadsheet error accounted for only about 0.3 percentage point of that difference. Most of the rest is caused by differences in the way the economists weighted the data. Even the UMass researchers found that higher debt is associated with slower growth. [Emphasis added.]

Not that critics will let the facts get in the way. “[L]iberal skeptics are seizing on this dustup to justify a slower-going approach to deficit-cutting,” despite the fact that even the critics of the Reinahrt-Rogoff research confirm the same basic point about the link between higher debt and lower growth.

Regular followers of the John Locke Foundation’s Shaftesbury Society might remember an April 2011 presentation in which N.C. State economist Thomas Grennes suggested that debt starts to cause problems when its reaches 77 percent of GDP.