In the linked study, Obermeyer and colleagues challenge conventional thinking about deaths related to war and force us to re-evaluate some well established assumptions about these deaths.1 Deaths in combatants and non-combatants are always underestimated during conflicts between armed groups in poor countries that are not national armies.2 Even in middle income developing countries, counts that are purported to be precise fail to include most of those killed.3 4

Obermeyer and colleagues used demographic data from world health surveys collected before and after conflicts in 13 countries over the past 50 years. The surveys collect information from one respondent for each household about sibling deaths, including whether the deaths were related to war. The data are then compared with those obtained through passive reports …