Behavioral Differences in Violence : The Case of Intra-Group Differences of Paramilitaries and Guerrillas in Colombia

In most empirical studies on civil wars, causes and determinants of conflict have been hitherto explored assuming that actors involved were either unitary or stable. However, if this intra-group homogeneity assumption does not hold, empirical econometric estimates may be biased and policy prescriptions are less reliable. We use Fixed Effects Finite Mixture Model (FE-FMM) approach to address this issue. This methodology provides a natural representation of heterogeneity when data originate from different latent classes and the affiliation is unknown. It allows to identify sub-populations within a population as well as the determinants of their behaviors. By combining various data sources for the period 2000-2005, we apply this new technique to the Colombian conflict. Our results confirm a behavioral heterogeneity in guerrilla’s armed groups and their distinct economic correlates so showing that different patterns of behavior exist. By contrast paramilitaries behave as a rather homogenous group