Science and politics of disaster death tolls

In August 2018, almost a year after Hurricane Maria swept through Puerto Rico, an academic study placed the death toll at about 46 times the number declared earlier by President Trump.1 The heated debate that followed the publication shows why these figures can be so controversial.23 High death tolls indicate the severity of a natural disaster but can also point to politically damaging inadequacies in the relief effort and to underlying poverty and inequality in the affected population.

The accurate documentation of deaths from disasters and conflicts helps create an objective historical record that informs national and international improvements in preparedness and response. Establishing who died, how, and where—basic epidemiological questions—also helps direct resources to the most vulnerable populations, increasing the effectiveness of humanitarian measures.

Counting deaths is politically sensitive, however, particularly in conflict settings where different combatants attribute civilian deaths to opposing forces for clear partisan reasons. Estimations of the death tolls from the conflicts in Darfur,4 …