Annals of Premature Accusations

Kevin Drum updates the score in the ongoing debate between Mann, Bradley and Hughes (climate scientists) and McIntyre and McKitrick (a couple of economists). The latter claim to have re-analyzed data from a famous paper of the former’s on global warming and found numerous errors that, when corrected, make the results go away. The climatologists have responded vigorously, saying that their critics have botched the job. Both sides are preparing further responses at the moment, so the issue is on hold.

That, however, hasn’t stopped Iain Murray from writing a quite inflammatory article in the NRO about all of this. The article tries to stamp the whole issue with his preferred spin:

bq. The whole affair bears strong resemblance to the recent Bellesiles controversy. Emory University historian Michael Bellesiles won a Bancroft Prize for his argument that gun ownership in early America was not widespread. It took an amateur historian, Clayton Cramer, to point out that this claim could not be substantiated on the basis of actual gun-ownership records. Eventually, an Emory University investigation strongly criticized Bellesiles, and the Bancroft Prize was withdrawn.

Given what we know about the present case, this is an indefensible comparison.

The work of a number of researchers showed beyond reasonable doubt that Bellesiles had fabricated his data. Murray is saying the same thing is happening here, as hardy amateurs show the professional scientists up as frauds. But nothing of the sort is even on the cards. At the absolute worst, a dataset has been incorrectly analyzed and a finding will need to be withdrawn. (It’s too early to say whether that’s what’s going to happen: probably not, if you ask me, but you never know.) There’s no suggestion from the accusers that data have been fabricated or that other researchers have been deliberately misled. Mann et al made their data available to McIntyre and McKitrick for reanalysis in the first place! This makes the comparison to Bellesiles absurd, even defamatory. Murray almost explains why the comparison is obtuse himself, saying “So far, it looks like the errors in Mann’s data set were accidental,” though he can’t resist putting in that “So far.” You can see what he really wants to have happen.

Well, he should have kept it to himself until he was sure about it. Murray’s desire to see conventional wisdom about climate change proved wrong has led him to excitably jump to conclusions before. He may now be having reservations about knocking out his column so quickly, as he published it before Mann et al released a rebuttal of the charges, which contains a robust defence of their paper. A longer response is forthcoming from them. “The issue is getting very technical at present,” Murray now says, linking to a calmly-worded piece asking that people not “jump to any conclusions” before all the details from both sides are available. Sounds sensible to me. It’s why you shouldn’t be slinging around accusations of the most serious kind of academic fraud, I’d have thought.