Statisticians grill surveyor of Iraqi casualties of war

The courtroom-style questioning came in a packed ballroom in Salt Lake City at the world's largest gathering of statisticians.

On the hot seat: A globe-trotting researcher who says his team's surveys of Iraqi households projected nearly 655,000 had died in the war as of July 2006, a number still 10 times higher than conventional estimates.

Leslie F. Roberts and others from Johns Hopkins University took accounts of births and deaths in some Iraqi households to estimate that the country's death rate had more than doubled after the 2003 invasion.

Number crunchers this week quibbled with Roberts' survey methods and blasted his refusal to release all his raw data for scrutiny - or any data to his worst critics. Some discounted him as an advocate for world peace, although none could find a major flaw in his surveys or analysis.

However, Stephen Fienberg, a professor of statistics at Carnegie Mellon University in Pittsburgh, said: ''I thought the surveys were pretty good for non-statisticians.''

Roberts, an epidemiologist, said he is opening a new front in the study of public health hazards: War. He has conducted about 30 mortality studies since 1990 in conflicts around the globe, including the Congo, where he was similarly accused of exaggerating war-related deaths.

Roberts organized two surveys of mortality in Iraqi households that were published last October in Britain's premier the medical journal, The Lancet. He acknowledged that the timing was meant to influence midterm U.S. elections.

''It puts you in a position where you are going to get attacked,'' said Fritz Scheuren, a senior fellow at the University of Chicago's National Opinion Research Center, who is trying to organize another Iraqi survey to see if he can match Roberts' results.

Scheuren, the American Statistical Association's former president, said he couldn't find anything wrong with The Lancet surveys.

He complained, however, that he wasn't able to get Roberts to reveal which of his Iraqi surveyors conducted which surveys, information that could reveal any bias in workers who compile consistently implausible results.

Roberts said he won't release the researchers' identities for fear of exposing them to retaliation. The Iraqi government has strongly disputed the findings.

The estimate covered everything from battlefield casualties to civilians dying for lack of routine medical care.