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I didn't go into more detail on the topic of "main street bias" because my article is already quite long. However, "main street bias" is unlikely to have significantly skewed the Lancet results for the following reasons: <ul><li>In the previous 2004 Lancet study, the researchers randomly selected locations in Iraq by using a GPS device to begin at a randomly-selected longitude and latitude. For the 2006 study, they felt that this completely random system was impractical because going around the country with an electronic device in their hand was likely to be interpreted as military activity, so they used the "randomly selected main street" technique as a means to <i>approximate</i> random selection of a location. It's not perfectly random, but it's a reasonable attempt to achieve randomness given the practical limitations posed by the level of violence and suspicion in Iraq. Can you suggest something better?</li> <li>The researchers didn't limit their visits to homes which were on the "residential street ... crossing the main street." Rather, they began at a randomly-selected address <i>on</i> that residential street and then visited the 40 homes closest to it, which would have taken them onto homes on other streets. Since the home on the residential street that served as the starting point was randomly-selected, there is no reason to expect that it would have been even close to the main street that the residential street intersected. It could be many blocks away. Calling this "main street bias" is in itself a misnomer. The correct term would be "streets that cross main streets bias."</li> <li>No one has presented any evidence, other than pure speculation, to suggest that people who live on main streets (or on residential streets that cross main streets) have been more likely to die than people who live on streets that do not intersect with main streets.</li> <li>The details of the Lancet results suggest that most people have been killed away from home anyway, which would vitiate any main street bias. For example, the male-to-female ratio shows that many more men than women have been killed: 3.4 male deaths for each female death, and 9.8 violent male deaths for each violent female death. If people were being killed at home, you would expect a higher percentage of female deaths, particularly since women tend to stay at home more than men.</li> <li>Even if we set aside all of the above considerations and assume that "main street bias" exists, I find it hard to imagine that it would have been significant enough to substantially alter the study's outcome. Can you give me any meaningful estimate for how much more likely you think it is for someone to be killed who lives on a street which intersects with a main street in Iraq, as opposed to someone who lives on a street that <i>doesn't</i> happen to intersect with a main street? I find it hard to imagine that the ratio could be so much as 2:1, and even if there was a 2:1 sampling bias, you'd still be left with an estimate of 300,000+ Iraqi deaths.</li> </ul> As for Jon Pedersen, his methodology was <i>not</i> similar to the Lancet study, as he himself notes in the URL you provided. For starters, his survey asked about a wide range of health and living conditions, whereas the Lancet study focused exclusively on mortality. That difference alone is in my opinion more likely to produce a discrepancy in outcomes between the two studies than any skewing due to "main street bias." The bottom line in all of this, though, is that we should be having <i>more</i> research like the Lancet study, from other research teams in addition to the Johns Hopkins group. If you question the methodology of the Lancet study, fine; then let's have additional studies that address your methodological concerns. In science, no single study should be presumed definitive, and the question of how many people are dying in Iraq (and what they're dying from) is important enough to deserve multiple studies.