I went through this with BRUCE here a few months ago.
The way they figured the 600k was grossly inaccurate. they used polls to estimate it.
It was a survey of random houses across Iraq, "by eight Iraqi physicians organized through Mustansiriya University in Baghdad and overseen by epidemiologists at Johns Hopkins University's Bloomberg School of Public Health.. They visited 1,849 randomly selected households that had an average of seven members each. One person in each household was asked about deaths in the 14 months before the invasion and in the period after.
The interviewers asked for death certificates 87 percent of the time; when they did, more than 90 percent of households produced certificates.
According to the survey results, Iraq's mortality rate in the year before the invasion was 5.5 deaths per 1,000 people; in the post-invasion period it was 13.3 deaths per 1,000 people per year. The difference between these rates was used to calculate "excess deaths."
Of the 629 deaths reported, 87 percent occurred after the invasion. A little more than 75 percent of the dead were men, with a greater male preponderance after the invasion. For violent post-invasion deaths, the male-to-female ratio was 10-to-1, with most victims between 15 and 44 years old.
Gunshot wounds caused 56 percent of violent deaths, with car bombs and other explosions causing 14 percent, according to the survey results. Of the violent deaths that occurred after the invasion, 31 percent were caused by coalition forces or airstrikes, the respondents said.
Burnham said that the estimate of Iraq's pre-invasion death rate -- 5.5 deaths per 1,000 people -- found in both of the Hopkins surveys was roughly the same estimate used by the CIA and the U.S. Census Bureau. He said he believes that attests to the accuracy of his team's results."
