Development, democracy, and mass killings

Using a newly assembled dataset spanning from 1820 to 1998, we study the relationship between the occurrence and magnitude of episodes of mass killing and the levels of development and democracy across countries and over time. Mass killings appear to be more likely at intermediate levels of income and less likely at very high levels of democracy. However, the estimated relationship between democracy and probability of mass killings is not linear in the full sample. In the XXth century, discrete improvements in democracy are systematically associated with episodes involving fewer victims.