Last week the New England Journal of Medicine (NEJM) published the latest study into the number of Iraqis killed since the US-led invasion in 2003. The article, which used the same cluster-sampling methodology as two previous studies published in the Lancet, drew a shocking conclusion: as of mid-2006, 151,000 Iraqis have died as a result of the war and occupation. This number is dramatically lower than the most recent Lancet estimate which put the number at about 655,000; however, the new research in the NEMJ is highly problematic and is likely a dramatic underestimate of Iraqi mortality since the war.

Counting Iraqi casualties has proven politically controversial. When the Lancet article appeared, George Bush dismissed it as “not credible.” More surprisingly, the Iraq Body Count website also attacked the study. Despite this, there was a broad consensus among epidemiologists that the Lancet number was the most reliable estimate of Iraqi casualties. The NEMJ study, undertaken by the august World Health Organization (WHO), will likely end this consensus.

This is because the NEMJ study had one great advantage over the Lancet study; the WHO has much better funding than the Johns Hopkins scientists who were behind the Lancet article. As a result the WHO surveyed many more people (1,086 clusters representing over 9,000 households) than did the Lancet researchers (who only managed 47 clusters representing 1,849 households).

Nevertheless, the Lancet study remains superior for reasons which are a trifle complex. The NEMJ scientists skipped over one in ten of their clusters because the violence in these clusters made interviewing too dangerous. The Lancet team, on the other hand, hit all of their clusters. This discrepancy between the two studies is of the utmost importance because the clusters the NEMJ researchers missed were primarily in high-violence, and therefore high-casualty, areas. 71 of the 115 missed clusters were in the tumultuous al-Anbar province, the rest were in Baghdad and the high-mortality provinces of Nineveh, and Wasit. In essence, the areas of Iraq where casualties most need to be counted were systematically under-sampled in the NEMJ study.

To make up for this deficiency, the WHO researchers augmented their data with extrapolations based on the estimates of the Iraq Body Count website. The website compiles mortality statistics by using the casualty counts from published media reports. As violence and chaos have engulfed Iraq, these reports have become less and less reliable. In short, the NEMJ scientists tried to compensate for their own shortcomings by supplementing their own inadequate numbers with even less trustworthy data.

In the final analysis, none of this matters all that much. Even the dramatic undercount offered by the NEMJ is five times greater than the only number that the US government has ever offered as an estimate for Iraqi casualties. Regardless of which side prevails in this scientific controversy, George Bush will go down in history as one of the most egregious mass murders of the 21st century. However, I think that we owe it to the scores of scores of scores of scores of Iraqi dead to at least count, to the very best of our ability, their numbers. To afford them in death the honor that we could not offer them in life, to say to them “you were human beings, you were important, and your deaths were unacceptable.”