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Saturday, October 30, 2004ADDENDUM: A skillful dissection here. UPDATE: Slate's Fred Kaplan says the Lancet paper's numbers are a dart board, not an estimate. Regarding the 100,000 "estimated" Iraqi civilian deaths since the war: The report's authors derive this figure by estimating how many Iraqis died in a 14-month period before the U.S. invasion, conducting surveys on how many died in a similar period after the invasion began (more on those surveys later), and subtracting the difference. That difference—the number of "extra" deaths in the post-invasion period—signifies the war's toll. That number is 98,000. But read the passage that cites the calculation more fully: We estimate there were 98,000 extra deaths (95% CI 8000-194 000) during the post-war period. Readers who are accustomed to perusing statistical documents know what the set of numbers in the parentheses means. For the other 99.9 percent of you, I'll spell it out in plain English—which, disturbingly, the study never does. It means that the authors are 95 percent confident that the war-caused deaths totaled some number between 8,000 and 194,000. (The number cited in plain language—98,000—is roughly at the halfway point in this absurdly vast range.) This isn't an estimate. It's a dart board. Imagine reading a poll reporting that George W. Bush will win somewhere between 4 percent and 96 percent of the votes in this Tuesday's election. You would say that this is a useless poll and that something must have gone terribly wrong with the sampling. The same is true of the Lancet article: It's a useless study; something went terribly wrong with the sampling. Read the whole thing, as they say. UPDATE II: More here. MORE: The blog Ragout, points out that the statistician mentioned in the Slate article is doubly credible. She's not only experienced in Iraqi civilian mortality rates, she was fired by the first Bush administration because they thought her numbers were too high after the first Gulf War. If she thinks the Lancet study is fishy, it's fishy. posted by Sydney on 10/30/2004 08:40:00 AM 0 comments 0 Comments: |
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