Do Non-State Armed Groups Influence Each Other in Attack Timing and Frequency? : Generating, Analyzing, and Comparing Empirical Data and Simulation

Non-State Armed Groups (NSAGs) operate in complex environments, commonly existing as one of the many organizations engaged in one-sided violent attacks against the state and/or the civilian population. When trying to explain the execution and timing of these attacks, most theories look at NSAGs’ internal organizational features or how these groups interact with the state or civilian population. In this study, we take a different approach: we use a self-exciting temporal model to ask if the behavior of one NSAG affects the behavior of other groups operating in the same country and if the actions of groups with actual ties (i.e., groups with some recognized relationship) have a larger effect than those with environmental ties (i.e., groups simply operating in the same country). We focus on three cases where multiple NSAGs operated at the same time: Afghanistan, Iraq, and Colombia, from 2001 to 2005. We find mixed results for the notion that the actions of one NSAG influence the actions of others operating in the same conflict. In Iraq and Afghanistan, we find evidence that NSAG actions do influence the timing of attacks by other NSAGs; however, there is no discernible link between NSAG actions and the timing of attacks in Colombia. Nevertheless, we do consistently find that there is no significant difference between the effect that actual or environmental ties could have in these three cases.