Measurement validity in historical conflict data: Comparing datasets from Spain

Abstract

Conflict research usually suffers from data availability problems, which sometimes motivates the use of use of proxy variables for violent events. But since they are usually the only alternative to measure violence patterns, there is not ground-truth data to compare them to. This limitation explains why there are no studies assessing their validity. This research note exploits a case where there are two sources on political violence: the Spanish Civil War. Comparing georeferenced mass graves and direct records of victimization, I show that the differences between these two datasets are not random but respond to different data generation processes, introducing important biases. Results highlight the need for a more careful assessment when using proxy variables for political violence.