Paul Krugman mentioned something interesting yesterday. He blogged about the (rightfully) shoddy work done by some researchers, Timothy Conley (Western Ontario University) and Bill Dupor (Ohio State), claiming that the Obama stimulus plan didn’t work. There are even pointers to blogs by Dean Baker and Noah Smith that take the study apart more thoroughly. So far, so good.
The latest anti-stimulus paper shows no sign of that kind of care. It makes no effort to control for the differential effects of bubble and bust. It uses odd variables on both the left and the right side of its equations. The instruments — variables used to correct for possible two-way causation — are weak and dubious. Dean Baker suspects data-mining, with reason; the best interpretation is that the authors tried something that happened to give the results they wanted, then stopped looking. (emphasis mine)
After reading the entry by Dean Baker, which more or less seems like a laundry list of criticisms of the original work on “how to get your statistics wrong.” But I see no mention of data mining or anything other than just bad statistics that could be at fault. The only explanation that I can think of is that Mr. Krugman may be using the term incorrectly.