Donald Gooch writes:
1. A one year period prior to the invasion was chosen for the pre-invasion period comparison baseline in the study. Why was this interval chosen? Note that this is a period with a coalition enforced no-fly zone in effect. Would a different interval have produced a different mortality rate? For example, what about one that included post-Gulf War reprisals? This is very significant. The pre-invasion mortality rate is integral to calculating the number of deaths attributable to the war in Iraq. Higher pre-invasion mortality rate, fewer deaths attributed to the war. And note, they get their estimate of the pre-invasion mortality rate from their sample. So a household is asked about deaths from each of the periods. They may be underestimating the deaths in the earliest period simply because it was so long ago.
2. I think there is a fundamental question as to whether this baseline-comparison model is appropriate for assessing the impact of the war on the number of deaths in Iraq. It is very sensitive to the baseline selected as well as the variance in deaths across clusters. While the authors acknowledge several possible sources of systematic bias in their sample (i.e. the possibility of over-sampling
higher-mortality clusters as a result of population migration), I don’t think they appreciate just how much of an effect that could have on their estimates. Their method does not and cannot account for the
essential non-randomness of warfare. Coalition forces do not drop bombs randomly. Insurgents do not plant IED’s or car-bombs randomly. As such their sample may be severely biased by the fact that individuals living in Iraq make rational decisions to move away from hot-spots when able to do so. Fewer people in the household means a higher mortality rate.
3. Why was no effort made to distinguish combatants from non-combatants? I understand that there is concern for risk to the interviewers (as stated in the article), but this is pretty important. The authors argue that this is the “this the deadliest international conflict of the 21st century” and that they have urged investigation into the “excess” mortality rate in Iraq. But what if a large percentage of that “excess” is, in fact, coalition forces killing insurgents? From a policy perspective, there doesn’t seem to be much logic in treating the death of an innocent child from an IED the same as the death of the terrorist planting the IUD at the hands of coalition forces…yet that is exactly what the study does. Note the study acknowledges that “Across Iraq, deaths and injuries from violent causes were concentrated in adolescent to middle age men.” The exact population from which combatants are drawn.