Development, Democracy, and Mass Killings

Using a newly assembled dataset spanning from 1820 to 1998, we study the relationship between the occurrence and cruelty of episodes of mass killing and the levels of development and democracy across countries and over time. We find that massacres are more likely at intermediate levels of income and less likely at very high levels of democracy, but we do not find evidence of a linear relationship between democracy and probability of mass killings. In the 20th century, discrete improvements in democracy are systematically associated with less cruel massacre episodes. Episodes at the highest levels of democracy and income involve relatively fewer victims.