Is the sample size large enough to yield reliable estimates?
Summary: The sample size is sufficiently large establish that the number of excess deaths in Iraq is 95 percent certain to be in the interval of 393-943 thousand, and much more likely to be near 655 thousand than any of these extremes. The use of a relatively small number of clusters does not “bias” the results but explains why the estimates are less precise than some other studies. The study was based on a “cluster sample survey” of 1849 households with 12,800 members. The households were distributed in 47 clusters across the whole of Iraq. Some commentators have claimed that this makes the results unreliable. The UK Prime Minister’s spokesman said: The problem with this was that they were using an extrapolation technique, from a relatively small sample Similarly, Steven Moore wrote a Wall Street Journal Op-ed describing the survey as “bogus” largely because it used an “an extraordinarily small number of cluster points”.
