The Lancet study — the sequel

I've been traveling quite a bit recently, so I'm quite late to the party on the eight page study published in The Lancet which concludes the following: Pre-invasion mortality rates were 5?5 per 1000 people per year (95% CI 4?3?7?1), compared with 13?3 per 1000 people per year (10?9?16?1) in the 40 months post-invasion. We estimate that as of July, 2006, there have been 654 965 (392 979?942 636) excess Iraqi deaths as a consequence of the war, which corresponds to 2?5% of the population in the study area. Of post-invasion deaths, 601 027 (426 369?793 663) were due to violence, the most common cause being gunfire. This is a follow-up to a 2004 study that raised a small ruckus prior to the presidential election claiming that the post-war mortality rate in Iraq was higher than the pre-war rate. The boys at Crooked Timber, as well as Tim Lambert, have been vigorously defending the study against conservative critics. Megan McArdle is more skeptical, has a raft of posts that critique the study. This post by Echidne of the Snakes is sympathetic to the study but also cognizant of its flaws, and is worth quoting on two points: Nobody is happy about the study findings, of course. Let me repeat that: Nobody is happy about the study findings; nobody wants to imagine that many horrible deaths and the suffering that goes along with those or the effect on the survivors.... These point estimates are not as "respectable" as showing them in cold numbers might suggest to some. This is because they are based on sample data and sample data derived from a modified form of random sampling. The confidence intervals that are given in the summary above reflect the added uncertainty caused by this.I have only one observation at this juncture. The problem with journalistic coverage of statistical analyses is that they tend to focus on the "headline number," ascribing a weight to it that it sometimes does not deserve. In this study, the 655,000 figure is much less important than the fact that the authors can claim with 95% certainty that at least 392,000 people have died in Iraq since the war started. That's the sobering fact. Readers are hereby invited to comment. UPDATE: Tyler Cowen posts on The Lancet study as well -- and highlights another important fact that explains a large part of my disenchantment with the Bush administration: [T]he sheer number of deaths is being overdebated. Steve Sailer notes: "The violent death toll in the third year of the war is more than triple what it was in the first year." That to me is the more telling estimate. A very high deaths total, taken alone, suggests (but does not prove) that the Iraqis were ready to start killing each other in great numbers the minute Saddam went away. The stronger that propensity, the less contingent it was upon the U.S. invasion, and the more likely it would have happened anyway, sooner or later. In that scenario the war greatly accelerated deaths. But short of giving Iraq an eternal dictator, that genie was already in the bottle. If the deaths are low at first but rising over time, it is more likely that a peaceful transition might have been possible, either through better postwar planning or by leaving Saddam in power and letting Iraqi events take some other course. That could make Bush policies look worse, not better. (emphasis added) ANOTHER UPDATE: The folks at Iraq Body Count are skeptical.