On Tue, Apr 16, 2013 at 1:25 PM, Sarah Goslee <sarah.gos...@gmail.com> wrote: > Given that we occasionally run into problems with comparing Excel > results to R results, and other spreadsheet-induced errors, I thought > this might be of interest. > > http://www.nextnewdeal.net/rortybomb/researchers-finally-replicated-reinhart-rogoff-and-there-are-serious-problems > > The punchline: > > "If this error turns out to be an actual mistake Reinhart-Rogoff made, > well, all I can hope is that future historians note that one of the > core empirical points providing the intellectual foundation for the > global move to austerity in the early 2010s was based on someone > accidentally not updating a row formula in Excel." > > Ouch. > > (Note: I know nothing about the site, the author of the article, or > the study in question. I was pointed to it by someone else. But if > true: highly problematic.) >
Herndon, Ash and Pollin (HAP), the authors of the critique, found that in the highest debt category the Excel error in Rienhart and Rogoff (RR) was -0.3 percent points compared to a total error (from that plus RR's other 2 mistakes) of -2.3 percentage points. See Figure 1 of HAP. Thus aside from the dubiousness of attributing the coding error in Excel to Excel itself it was not the main source of the discrepancy. Also even if one backs out all three errors that they found, the key conclusion that GDP growth is declining with debt still occurs (but to a lesser extent) as pointed out by RR in an initial responding email reported by Bloomberg News. The key takeaway here is really unrelated to Excel but rather is that until data and analyses are shared or made public so that the analysis can be reproduced one cannot have any real confidence in research results. RR http://www.nber.org/papers/w15639.pdf HAP http://www.peri.umass.edu/fileadmin/pdf/working_papers/working_papers_301-350/WP322.pdf Bloomberg News http://www.bloomberg.com/news/2013-04-16/reinhart-rogoff-paper-cited-by-ryan-faulted-for-serious-errors-.html -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
