Assassinations are a persistent feature of the political landscape. Using a new data set of assassination attempts on all world leaders from 1875 to 2004, we exploit inherent randomness in the success or failure of assassination attempts to identify assassination's effects. We find that, on average, successful assassinations of autocrats produce sustained moves toward democracy. We also find that assassinations affect the intensity of small-scale conflicts. The results document a contemporary source of institutional change, inform theories of conflict, and show that small sources of randomness can have a pronounced effect on history. (Robert S. Miola 1985). An ethical basis for "tyrannicide" was promulgated by John of Salisbury in the 12 th century and further articulated by Milton in the late Renaissance (e.g. Carey J. Nederman 1988). In the United States, government-sponsored assassination was not formally outlawed until 1976, and here only by Executive Orders that are themselves the subject of renewed debate.
1To understand assassination -as an influence in history, as a policy, even as a normative matter -it is important to understand whether assassinations actually change the course of events. On this topic there is considerable debate, primarily among historians who have focused on individual assassinations or small collections of case studies.2 In this paper, we assess the impact of assassination using a data-driven approach. 3 Specifically, we focus on the assassination of national leaders and examine its effects on two important outcomes: institutional change and war. The results show substantial effects of assassinations, informing our understanding of assassination and more broadly informing theories of institutional change and conflict.Analyzing the effects of assassination is difficult. While some assassinations may be associated with historical turning points, the direction of causation is difficult to establish, especially since assassination attempts often occur (as we will show) in times of crisis, such as during war. To overcome this problem, we employ a large set of assassination attempts and use the "failures" as controls for the "successes". To focus on the cases where the success or failure of the attempt was most likely determined by chance, we consider only those attempts in which the weapon was actually used -the gun fired, the bomb exploded, etc. The identification assumption is that, although attempts on leaders' lives may be driven by historical circumstances, conditional on trying to kill a leader the success or failure of the attempt can be treated as plausibly exogenous. For example, Hitler's early departure from the beer hall in 1939, which may have saved his life, came only because bad weather prevented him from flying back to Berlin, forcing him to leave early for a train.2 For example, Miles Hudson (2000) discusses a set of assassinations and argues that assassination has little effect, echoing Disraeli's view. However, the murder of Archduke Ferdinand is often described as ...