Friday, December 09, 2005
...four calling birds, three heart attacks, two turtle doves...
If I ever teach the concept of causal inference from discontinuity again, the graph above is an example I will use. The graph is the stock price of Merck (a corporation sufficiently large as to be one of the 30 used to compute the Dow Jones index). Sometime during this two year period, Merck withdrew the drug Vioxx from the market amidst safety concerns. I'll leave it as an exercise for the blogpost reader as to exactly when they think this event occurred.
(Merck is in the news today because an "expression of concern" has been published by the New England Journal of Medicine over the strange omission of three cardiovascular events among patients taking Vioxx in trial results published in NEJM four years before Vioxx was withdrawn. So much can be said about those three heart attacks. For anybody interested in the intersection of corpora of knowledge, corporations, and corpses, the Vioxx story is absolutely, utterly, completely fascinating. If any such person is casting about for, say, a thesis topic, the intellectual possibilities of Vioxx as a case study are enormous. I mean, just look at the graph above and realize how much Merck had riding on the science of Vioxx panning out.)