Oops. Forgot to Carry The Two.

This makes me cringe:

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.

I hear these reports of Excel errors [1] all the time but rarely do I hear of one that literally impacts the underpinnings for economic decisions across the entire world. In defense it sounds like this error by itself doesn’t make a huge difference but there are some other concerns with the model that, if true, means it is inconclusive at best. Public service announcement: always triple check your formulas.

The second thing I want to point out is that Excel is still the most indispensable piece of software in almost every business and government organization. The humble spreadsheet, nearly forty years old, runs the world’s economy. Considering this academic study shows that almost 90% of spreadsheets carry errors and, well, that should make us all want to hide our money in a box buried in the backyard.

Finally, many a word has been written over the past months regarding Microsoft’s “no compromise” Windows 8. Most have rightly pointed out that making no compromises is a compromise in and of itself and that legacy mode is horrible. But Excel specifically (and Office in general) is exactly why Microsoft made this decision. Could Microsoft have given users some of Excel in the Metro interface? Absolutely. But some of Excel isn’t good enough. When it comes to the power users who spend lots of money with Microsoft, Excel is an all or nothing proposition.

[1] I’m referring to data errors, not errors of Excel’s calculation engine. Excel does, however, have some calculation issues mostly because of backwards compatibility. As one example, when Visicalc wrote the original Net Present Value it actually didn’t calculate NPV; it calculated discounted cash flows. Lotus 1-2-3 copied it and so did Excel. =NPV() in Excel needs a modification to correctly calculate Net Present Value. (A great explanation is here.)