Tech Central Station has published Tim Worstall’s admission that his critique of the Lancet Iraq study was completely wrong:
Further to my article of Friday on this subject. I’m afraid I mangled the statistical argument. My inadequate knowledge of the subject led me to make an argument that is incorrect. I stand by my contention that there is something fishy about this study (leaving aside the politically motivated timing of its publication, something the author has been clear about himself) yet have to admit that I have not found it, leaving me with nothing but personal prejudice upon which to stand my argument. I would also like to make clear that this subject was not “assigned” to me, the idea, research, argument and errors were all my own, as was my request for this clarification. Just in case you are wondering, being fact checked by the Pajamahaddin and being found in error does hurt and I hope that future writings will be, where necessary, so corrected.”
On his blog Worstall thanks Daniel Davies and me for the correction. Such decent behaviour is unfortunately not common at Tech Central Station. Authors like John Lott and Iain Murray just repeat their false claims, while Glenn Reynolds posts a correction but does not acknowledge the source.
Tech Central Station didn’t just post Worstall’s correction by itself. They have had a second attempt at debunking the Lancet study, posting an article by Michael Fumento. Fumento argues:
the researchers didn’t feel themselves bound by anything official, like death certificates. Interviews were just fine. “In the Iraqi culture it was unlikely for respondents to fabricate deaths,” they wrote.
Unfortunately, Fumento seems to have missed the immediately preceding sentences in the Lancet paper, where they noted that, when asked, 81% confirmed with death certificates:
In 63 of 78 (81%) households where confirmations were attempted, respondents were able to produce the death certificate for the decedent. When households could not produce the death certificate, interviewers felt in all cases that the explanation offered was reasonable eg, the death had been very recent, the certificate was locked away and only the husband who was not home had the key. We think it is unlikely that deaths were falsely recorded.
Fumento’s “killer” argument is:
Cluster sampling can be valid if it uses reliable data, rather than on inherently unreliable self-reporting. But it can also be easily skewed by picking out hotspots — like determining how much of a nation’s population wears dentures by surveying only nursing homes.
In fact, intentionally or otherwise, that’s pretty much what The Lancet did. Most of the clusters had no deaths whatsoever. But here’s the real bombshell: “Two-thirds of all violent deaths were reported in one cluster in the city of Falluja,” the journal reported. That’s it; game over; report worthless.
Trouble is, Fumento has once more been extraordinarily careless in his reading of the study. Here are the two sentences in the report that follow the one he quoted:
If we exclude the Falluja data, the risk of death is 1.5-fold (1.1-2.3) higher after the invasion. We estimate that 98 000 more deaths than expected (8000-194 000) happened after the invasion outside of Falluja and far more if the outlier Falluja cluster is included.
That’s right, they properly excluded the outlier Falluja in their estimate of 98,000 and Fumento didn’t notice this fact. That’s it; game over; Fumento article worthless.
I’m starting to feel embarrassed for Tech Central Station. Do you think they’ll have a third go at the Lancet?
Also of interest is Chris Lightfoot’s demolition of more lame critiques of the study.