http://finance.yahoo.com/blogs/daily-ticker/economic-argument-over-paul-krugman-won-150247189.html
An academic paper that found that a ratio of 90%-debt-to-GDP was a threshold above which countries experienced slow or no economic growth was found to contain an arithmetic calculation error.
Once the error was corrected, the “90% debt-to-GDP threshold” instantly disappeared.
Dammit, Tugwit!