The Iraqi Death Toll Revisited

The controversy continues over how many Iraqis have died as a result of the U.S. invasion and subsequent occupation. Yesterday, Sheldon Rampton, who runs the indispensable PR Watch from Madison, Wisc., wrote this analysis in a comment to my earlier post. I thought his insight into what may have accounted for the differences in the two studies in question worth bringing to the fore, so here it is:

The Lancet study's figure of 600,000 cannot be directly compared to the 150,000 figure just reported in the study conducted by the WHO and the Iraqi government. The Lancet study used a different methodology and attempted to calculate the TOTAL number of people -- including both civilians and combatants -- killed as a result of the war, whereas the WHO/Iraqi study came up with an estimate just of the number of CIVILIANS killed by VIOLENCE.

As the WHO/Iraqi researchers stated in a Q&A summary accompanying their study, "The non-violent mortality rate increased by about 60%, from 3.07 deaths per 1000 people per year before the invasion to 4.92 deaths per 1000 people per year in the post-invasion period. This was not further addressed in this analysis, which focused on mortality due to violent deaths."

Since Iraq has an estimated population of 27 million people, an increase of 1.85 deaths per 1,000 people per year from non-violent causes would add another 50,000 deaths per year, or another 150,000 deaths during the three-year period of the study. That's a very crude estimate, and someone with a more careful look at the data could probably refine it further, but it suggests that if we really want to compare the two studies, the difference is between the Lancet's 600,000 deaths vs. about 300,000 deaths according to the WHO/Iraqi study. That's still a significant difference, but not as large a difference as the popular press is making it out to be.

In addition, there are also some methodological differences between the studies which may account for some of the difference in results. First, the WHO/Iraqi study didn't visit some areas of the country due to concerns for the safety of their field researchers, and instead instead relied statistical extrapolations for those areas based on numbers compiled by Iraq Body Count, an organization that tallies deaths reported in newspapers and other public sources. If the areas most dangerous to field researchers also happen to be the areas where journalists are least likely to report, this extrapolation from IBC's data may have produced an undercount.

A second methodological difference is that the WHO/Iraqi study was conducted later than the Lancet study. In the interim, I believe something on the order of 2 million people fled the country to escape violence. Of course, if a family flees the country after a member of the household has been killed, there will be no one home to report that person's death to the field researchers when they come knocking, thus producing an undercount (which would be exaggerated further if people who had family members killed were more likely to flee the country than people who stayed).

I don't have any way of quantifying the possible effect that these two factors may have had on the study's results, but I think it's jumping the gun to assume that the two studies are in huge contradiction with each other.