Saturday, September 22, 2007

ORB’s September Survey and Baghdad Deaths

ORB has quietly revised the religion data in their survey of Iraq released earlier in September, but there are still strange things about the Baghdad results.

The gender demographics for Baghdad still seem to conflict with the reported violent death rate. 421 households, the weighted number for Baghdad, would have had about 2750 members in 2003, if their size was typical of Iraq, with about 700 adult males and a like number of adult females. According to both media reports collected by Iraq Body Count and those polls that asked the question, adult males represent about 90% of the violent deaths in Iraq since the invasion. It is plausible to estimate that of the 295 violent deaths reported in the weighted ORB poll, about 250 were adult males (18 or older), 15 were adult females, and the rest were children. The adult survivors would then be about 450 males and 685 females: 40% male and 60% female. Children coming of age since 2003 might reduce the imbalance slightly: to 42%/58%, assuming no sexual disparity in deaths among those who were 14-17 at the time of the invasion. This last is not necessarily a plausible assumption: 14-17 year old males are probably at higher risk than females of the same age.

ORB reported that their adult Baghdad respondents were 49% male. Plausible extrapolation of the reported violent death rate above, and the age and gender of reported victims of violent death in Iraq, suggest that given that death rate Baghdad adults should only be 40-42% male. That’s a significant conflict

There’s another reason to distrust the Baghdad death rate in the September ORB poll. In a poll they released in March, they asked a similar but broader question: had the respondent had a relative murdered in the past three years? 26% said yes: 31% said so in Baghdad, and 24 % in the rest of the country. In the September poll, 12% outside Baghdad has lost at least one household member. If we assume that the Iraq Body Count was a fairly consistent undercount during the preceding six months and use it to estimate the change in cumulative violent deaths, that would have been 10% at the time of the March survey. Outside Baghdad, the two polls seem in reasonable agreement: it seems entirely plausible that an extended family in Iraq is about 2.5 times the size of the immediate household.

But extrapolating the March Baghdad responses forward on the same basis predicts a household death rate of 15%: higher than the rest of Iraq, but less than a third of that reported for Baghdad in the September poll. Alternatively, projecting the September Baghdad results backwards implies that Baghdad extended families are only 25% larger than the immediate household living under one roof. That seems highly implausible.

1 comment:

Josephus said...

Will,

Interesting commentary on the ORB poll, however I'm not sure that your first point about the discrepancies in the Baghdad respondents is very convincing. Why would one make the assumption that the ratio of male to female phone survey respondents should mirror the ratio of the adult population? It seems like there are a number of unknown factors that play into respondent demographics (social norms, unemployment rates, distribution of call times, etc.). It's possible I have misread your argument (it happens frequently), and, in that case feel free to correct me. Thanks.