Recent Articles on L2
Several recent (to me) articles about the Lancet surveys are worth reading.
First, a tour de force (pdf) from Michael Spagat: "Ethical and Data-Integrity Problems in the Second Lancet Survey of Mortality in Iraq." This is the paper that I wanted to write last summer, but was not smart or organized enough to do. Michael will be presenting this paper at JSM in August.
Second, "Estimating mortality in civil conflicts: lessons from Iraq" by Debarati Guha-Sapir and Olivier Degomme (pdf) is critical of L2. The authors identify several "errors and methodological weaknesses" of L2 and write:
This is less than 1/4 of the comparable L2 estimate of 601,000.
Third, a 2006 working paper (pdf) by Mark J. van der Laan. He argues that the reported confidence interval for L2 is significantly too narrow.
Fourth, the IFHS study. They estimate about 151,000 violent deaths over the same period as L2. Again, this is around 1/4 the L2 estimate. M. Ali, one of the authors, will be presenting on my panel at JSM.
Good stuff all.
Where does that leave my estimate of excess war deaths? Time to update with the information in these studies. Recall that I wrote two years ago:
Then, last month, I updated to:
This still seems OK, but I think that the upper bound can start to come down. When experience scholars like the folks at IFHS and CRED come up with independent (?) estimates with upper confidence intervals well below 500,000, then I can be fairly sure that this is too conservative. So, now I go with 125,000 (shifting a little lower than IFHS because I am impressed with the view that the IFHS estimate does too much adjustment for dangerous clusters that were not sampled) and a range of 0 to 300,000.
All of this, of course, depends on the assumption that the mortality rate in Iraq, in the absence of war, would have been similar to that of Iraq in 2002 to 2003. In other words, I assume that Sadam would not have attacked Iran, gassed the Kurds, taken revenge on the Shiites and so on. Whatever probability you assign to those events, you should decrease your excess death estimates accordingly.
First, a tour de force (pdf) from Michael Spagat: "Ethical and Data-Integrity Problems in the Second Lancet Survey of Mortality in Iraq." This is the paper that I wanted to write last summer, but was not smart or organized enough to do. Michael will be presenting this paper at JSM in August.
Second, "Estimating mortality in civil conflicts: lessons from Iraq" by Debarati Guha-Sapir and Olivier Degomme (pdf) is critical of L2. The authors identify several "errors and methodological weaknesses" of L2 and write:
Our re-estimation of total war-related death toll for Iraq from the invasion until June 2006 is therefore around 125,000.
This is less than 1/4 of the comparable L2 estimate of 601,000.
Third, a 2006 working paper (pdf) by Mark J. van der Laan. He argues that the reported confidence interval for L2 is significantly too narrow.
Fourth, the IFHS study. They estimate about 151,000 violent deaths over the same period as L2. Again, this is around 1/4 the L2 estimate. M. Ali, one of the authors, will be presenting on my panel at JSM.
Good stuff all.
Where does that leave my estimate of excess war deaths? Time to update with the information in these studies. Recall that I wrote two years ago:
If I had to bet, I would provide much wider confidence intervals than either the Lancet authors or most of their critics. Burnham et al. (2006) estimate 650,000 "excess deaths" since the start of the war with a 95% confidence interval of 400,000 to 950,000. My own estimate would center around 300,000 and range from 0 to 1.2 million.
Then, last month, I updated to:
So, my new estimate is 150,000 (at first glance, this new paper seems much better than L1 or L2) with a confidence interval of 0 to 500,000.
This still seems OK, but I think that the upper bound can start to come down. When experience scholars like the folks at IFHS and CRED come up with independent (?) estimates with upper confidence intervals well below 500,000, then I can be fairly sure that this is too conservative. So, now I go with 125,000 (shifting a little lower than IFHS because I am impressed with the view that the IFHS estimate does too much adjustment for dangerous clusters that were not sampled) and a range of 0 to 300,000.
All of this, of course, depends on the assumption that the mortality rate in Iraq, in the absence of war, would have been similar to that of Iraq in 2002 to 2003. In other words, I assume that Sadam would not have attacked Iran, gassed the Kurds, taken revenge on the Shiites and so on. Whatever probability you assign to those events, you should decrease your excess death estimates accordingly.
2 Comments:
"a tour de force"?
Are you going to edit this anytime soon?
Best regards,
trane
Hi David.
As you didn't reply to my post on the Deltoid blog on 12 Feb this year, here it is again. Would be grateful for your thoughts...
Reply to David Kane. I am quite concerned that too many people are not aware of Spagat's own conflict of interest which has never been debated.
Has no one stopped to consider for one minute the reasons why someone like Spagat would spend so much time and energy trying to discredit the Lancet reports?
The answer is quite simple: because if he doesn't, his own work becomes discredited.
Spagat, according to his own website, launched "a new web site called Civil Conflict Analysis Resources", or CERAC, which he hopes "will become a major resource for conflict researchers, especially economists and political scientists."
According to Spagat, CERAC is "a think tank that we have set up in Bogota specializing in the analysis of conflict and violence" (the 'we' being Spagat and his colleague PhD student Jorge Restrepo).
(The wording has now been changed)
At the CERAC website there are published several research papers. In several of these CERAC research papers, calculations and conclusions were made, based on data for civilian killings provided by Iraq Body Count (IBC).
Cerac
Research
Apart from CERAC using IBC as part of its Integrated Iraq Dataset (CIID), it transpires that the Dept. of Economics at the Royal Holloway (Spagat's Dept), University of London, also uses IBC in its country specific datasets (click on 'datasets' at link)
If IBC figures are a gross undercount and distortion, and the Lancet figures are closer to the true number, then the conclusions reached in Spagat's research papers and indeed any other that used the IBC figures, could and would be seriously compromised. Therefore, Spagat cannot possibly be considered an 'honest broker' in this affair but is merely defending his own interests which include funding...
I put these points to Dr. Madelyn Hsiao-Rei Hicks, who also briefly entered the fray to discredit Lancet in favour of IBC.
She never replied, but interestingly she is also a research associate of CERAC, and as such, a colleague of Prof. Mike Spagat
The shocking thing is that in her letter to the Lancet criticising the Iraq Mortality Study, she has stated quite clearly at the bottom "I declare that I have no conflict of interest." A porky if ever there was one...
Has Spagat ever signed this declaration?
Links are available in the original posting:
http://scienceblogs.com/deltoid/2008/02/neil_munro_goes_after_riyadh_l.php
My original blog posting here:
http://dailysketcher.blogspot.com/2006/11/professors-michael-spagat-neil.html
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