Tuesday, April 16, 2013
Ken Rogoff and Carmen Reinhart, Meet Marc Hauser
In violation of the solidarity that ought to exist between ex-chessplayers (albeit at very different levels of achievement), when I hear about the errors and dubious data selection and modeling choices of Rogoff and Reinhart, my thoughts turn to Marc Hauser.
Hauser, you may recall, was a leading evolutionary biologist and something of a pop culture star, who cranked out high profile papers from his lab at Harvard. Eventually it was determined that he had systematically doctored evidence in order to produce the results that fit the theory he was peddling. There was a formal inquiry, and he left the institution in disgrace.
I bear no personal animosity toward Hauser. For all I know he may have drifted into the methods that got him into trouble a little at a time, and he may have seen each step as temporary, small and excusable. A science, however, has to be hard-nosed about this. As I’ve argued elsewhere (here, here and here), if there’s a core feature that distinguishes science from other human activities and renders it historically progressive (it gets better over time), it is the enormous weight sciences place on Type I error, the risk of false positives, compared to Type II. This enables a division of labor to flourish, since specialists can rely on the carefully vetted findings of other specialists. It also means that there will be rarely a step backward, a shift of a scientific field toward greater error over time from which it later has to retreat. You can’t say this about poetry, politics or palmistry.
Or economics. As far as I can tell, there are no serious consequences for economists who commit egregious Type I errors. They get to go on with their careers, and everyone just shrugs it off. No Marc Hausers here, folks.
So much the worse for us. Naturally, in applied work the risks of false positives and negatives have to be balanced by their respective costs in good Bayesian fashion, and we can live with a stream of Type I errors if that minimizes the overall cost of poor decision-making. But in matters of theory, where basic economic relationships are putatively identified, there should be no excuse for errors of the sort R&R appear to have committed. They were made more culpable by the pair’s long, long delay in releasing their source data.
These economists deserve a formal review—just like Marc Hauser.