Pinning down the role of social ties in the decision to protest has been notoriously elusive, largely due to data limitations. Social media and their global use by protesters offer an unprecedented opportunity to observe real-time social ties and online behavior, though often without an attendant measure of real-world behavior. We collect data on Twitter activity during the 2015 Charlie Hebdo protest in Paris, which, unusually, record real-world protest attendance and network structure measured beyond egocentric networks. We devise a test of social theories of protest that hold that participation depends on exposure to others' intentions and network position determines exposure. Our findings are strongly consistent with these theories, showing that protesters are significantly more connected to one another via direct, indirect, triadic, and reciprocated ties than comparable nonprotesters. These results offer the first large-scale empirical support for the claim that social network structure has consequences for protest participation.

Active research on a wide range of political contexts centers on ethnicity's role in collective action. Many theories posit that information flows more easily in ethnically homogeneous areas, facilitating collective action, because social networks among coethnics are denser. Although this characterization is ubiquitous, little empirical work assesses it. Through a novel field experiment in a matched pair of villages in rural Uganda, this article directly examines word‐of‐mouth information spread and its relationship to ethnic diversity and networks. As expected, information spread more widely in the homogeneous village. However, unexpectedly, the more diverse village's network is significantly denser. Using unusually detailed network data, we offer an explanation for why network density may hamper information dissemination in heterogeneous areas, showing why even slight hesitation to share information with people from other groups can have large aggregate effects.

While rumors predominate in conflict settings, researchers have not identified whether and why they influence the start of organized armed conflict. In this paper, we advance a new conceptualization of initial rebel group formation that aims to do so. We present a simple game-theoretic network model to show why the structure of trusted communication networks among civilians where rebel groups form—which carry credible rumors about the rebels—can influence whether incipient rebels become viable. We argue further that in rural Sub-Saharan Africa, kinship network structures favorable to nascent rebels often underlie ethnically homogeneous localities, but not heterogeneous ones. In doing so, we advance a new explanation for why ethnicity influences conflict onset, and show why ethnic grievances may not be a necessary condition for the emergence of “ethnic rebellion.” We illustrate our arguments using new evidence from Uganda that provides a rare window into rebel group formation.

Knowledge creation is a social enterprise, especially in political science. Sharing new findings widely and quickly is essential for progress. Scholars can now use Twitter to rapidly disseminate ideas, and many do. What are the implications of this new tool? Who uses it, how do they use it, and what are the implications for exacerbating or ameliorating existing inequalities in terms of research dissemination and attention? We construct a novel dataset of all 1,236 political science professors at PhD-granting institutions in the United States who have a Twitter account to answer these questions. We find that female scholars and those on the tenure track are more likely to use Twitter, especially for the dissemination of research. However, we consistently find that research by men shared on Twitter is more likely to be passed along further by men than research by women.

Active research on a wide range of political contexts centers on ethnicity's role in collective action. Many theories posit that information flows more easily in ethnically homogeneous areas, facilitating collective action, because social networks among coethnics are denser. Although this characterization is ubiquitous, little empirical work assesses it. Through a novel field experiment in a matched pair of villages in rural Uganda, this article directly examines word-of-mouth information spread and its relationship to ethnic diversity and networks. As expected, information spread more widely in the homogeneous village. However, unexpectedly, the more diverse village's network is significantly denser. Using unusually detailed network data, we offer an explanation for why network density may hamper information dissemination in heterogeneous areas, showing why even slight hesitation to share information with people from other groups can have large aggregate effects.