Obermeyer, Murray and Gakidou
OMG's key claim, for purposes of Lancet aficionados, is that "media estimates capture on average a third of the number of deaths estimates from a population based surveys." This matters because Les Roberts has been running around for years claiming that passive surveillance (as Iraq Body Count uses) is a horrible method of estimating mortality and never (except possibly in places like Bosnia) captures more than a small percentage of all deaths. (In fairness to Roberts, this is a new article and so, perhaps, his previous claims were justified by the research he had access to at the time.)
Will Roberts now acknowledge this? Time will tell.
The paragraph most directly relevant to disputes over Iraq mortality is:
As a final point of comparison, we applied our correction method, derived from the comparison of survey estimates with Uppsala/PRIO data, to data from the Iraq Body Count project’s most recent report of 86,539 (the midpoint of the 82,772 to 90,305 range reported in April 2008) dead in Iraq since 2003. Our adjusted estimate of 184,000 violent deaths related to war falls between the Iraq Family Health Survey estimate of 151,000 (104,000 to 223,000) and the 601,000 estimate from the second Iraq mortality survey by Burnham and colleagues. [footnotes omitted]
1) Tim Lambert enjoys making a listing of various (reputable) estimates of mortality in Iraq. Example here Now, I might argue that, given all the problems that ORB has had, its estimate does not belong in Tim's collection. But there can be no doubt that OMG's estimate does belong. Will Tim add it?
2) If your main interest is judging the quality of L2, then a better comparison would have used the IBC numbers to July 2006 (mid-point 47,668), thus covering the same time period as L2 and IFHS. I am not sure what the exact formula is that allows OMG to go from 86,539 to 184,000. Assume that we can just apply this ratio (184,000/86,539 = 2.13) to the IBC estimate of 47,668. That would yield a violent death estimate of 102,000. Recall that, 2 years ago, Jon Pedersen estimated violent deaths at 100,000. Moreover, the IFHS estimate would be lowered from 151,000 to around 100,000 if you removed the "arbitrary fudge factor" (in Debarati Guha-Sapir's marvelous phrasing) that IFHS employs.
Call me crazy, but I would say that the emerging scientific consensus is that approximately 100,000 excess war-related violent deaths had occurred in Iraq through June 2006. This is 1/3 lower than 150,000 (0 -- 500,000) estimate that I was comfortable with earlier in this year. Given all the new research since then, I update my estimate to 100,000 with a 95% confidence intervals of (0 -- 300,000).
[Those who think that a lower bound of zero is too low should remember that the definition of "excess" implies a comparison to what would have happened in a counterfactual world without a US invasion/occupation. Although I do not think that it is likely that Saddam would have engaged in substantial internal (against Kurds/Shia) or external (against Iran/Kuwait) aggression, it is not impossible that he would have. Those (possible) violent deaths were prevented by the war. If the comparison is against mortality in Iraq in 2002, then the lower bound should be raised substantially.]
So, if IFHS and IBC+OMG are consistent with each other and with the opinions of informed observers like Pedersen and Guha-Sapir, why does L2 estimate violent mortality approximately 6 times higher? I think that the raw data underlying L2 is not reliable.