Adventures in Onionism

This article by Mark Bittman has pretty interesting stuff on causality in medicine, given that it's impossible to run a randomized trial where you randomize a lifetime of smoking or eating lots of sugar. Teaching is exhausting, but fun. This paper by Nunn & Puga from REStat last year is my favorite article I've taught so far this semester. They claim ruggedness is bad for GDP in most places of the world for obvious reasons (transport costs), but it's good for GDP in Africa because it reduced the slave trade, which is even worse. Really no fancy econometrics, just a simple design and lots of robustness checks. You don't want to run a regression of GDP on ruggedness because omitted variables will obviously bias your estimate, but it's perhaps less bad to run one on ruggedness, an Africa indicator, and the interaction of ruggedness and the Africa indicator. The coefficient on ruggedness is still biased, but the coefficient on the interaction is only biased if t...

Just finished reading Eat and Run: My Unlikely Journey to Ultramarathon Greatness by Scott Jurek (with Steve Friedman). While I'm happy that the book has motivated me to run a little (lot) more consistently, I mostly didn't like it, for two reasons. One, the writing was tired and cliched. Two, there were too many pseudo-scientific and psuedo-spiritual claims about the source of his running prowess (e.g. homeopathy, cleansing toxins, etc.). For good measure they mentioned one of the many horrible statistical studies showing that sitting makes people die early (tangent you've heard before: just because you control for smoking and other aspects of lifestyle doesn't mean you get at causality. If there is anything in the world that you did not include in your analysis that is correlated with both sitting and life expectancy, then your estimate of the effect of sitting on life expectancy is incorrect. And if there are plenty of things that you can measure that are correlated ...