Last week he was asked about a new estimate of the number of
Iraqis killed as a result of the U.S.-led invasion. He said the paper
was "pretty well discredited."
The study, published in the British medical journal The Lancet, gives a range of 400,000-800,000
deaths due to the war and its violent aftermath. That's not only way
out of line with U.S. government estimates -- some ten times less -- but
also with other counts. Iraq
Body Count, a London-based antiwar group that is no way a shill for
the occupation, puts the number of civilians killed since 2003 at
49,000. The United Nations Development Program estimate is 18,000-29,000
up until mid-2004.
People who oppose this misguided war will be tempted to accept the
larger number offered by the Lancet authors, Gilbert Burnham, Riyadh
Lafta, Shannon Doocy and Les Roberts. Obviously, though, their numbers
are so different because they use a different method of getting their
information. Unless you value propaganda above truth, then, you need
to know: Is their approach more accurate than that used by others?
The Lancet team sampled 1,849 households all over Iraq, counted
incidents of violent death in each, before and after the invasion, and
then proposed that those rates apply to the entire population of 27
million Iraqis. This is how epidemiologists would estimate rates of
death from measles or malaria -- take a sample and then project it onto
the whole. The assumption there, of course, is that all people exposed
to an epidemic are equally likely to catch the disease.
Is that assumption safe? Is death in war a phenomenon like measles?
Neil Johnson, a physicist at Oxford who studies patterns in violent
conflicts, believes that the answer is no. In an epidemic, he told me,
it is safe to assume that all people have an equal chance of catching
the disease. But in war and its violent aftermath, this assumption
can't possibly be correct. Differences among Shiites and Sunni,
politically engaged and remote, rich and poor, region and region -- all
of these seem likely to have an impact. So if epidemiological methods
produce a number out of line with other methods, it is at least worth
asking if the problem is with the epidemiologists.
Johnson and his collaborator Michael Spagat, an economist at the
University of London, Royal Holloway, believe they have found just such
a fatal flaw -- an error that stems from mistakenly assuming that war
deaths work like deaths from illness. It seems all the households
surveyed by the Lancet authors were on main roads or at intersections of
smaller streets with major arteries. It does not take a detailed
knowledge of warfare to imagine how households in those locations would
be more likely to report car bombings, market-place explosions, and
attacks on vehicles.
For more on the burgeoning controversy, see today's reports in
EX=0&sortspec=date&resourcetype=HWCIT">Science, and Nature.
And keep in mind that the issue is not which political stance is better
served by these figures, but simply whether they are sound.
Follow David Berreby on Twitter: www.twitter.com/davidberreby