Security in the Absence of a State: Traditional Authority, Livestock Trading, and Maritime Piracy in Northern Somalia∗ Avidit Acharya† Robin Harding‡ J. Andrew Harris§ March 19, 2020 Abstract Without a strong state, how do institutions emerge to limit the impact of one group's predation on another's economic activities? Motivated by the case of northern Somalia, we develop a model that highlights the monitoring challenges that groups face in making cooperation self-enforcing, and two key factors that influence their likelihood of overcoming this challenge: the ratio of economic interests across productive and predatory sectors, and the existence of informal income-sharing institutions. Our model explains why conflicts between pirates and livestock traders can be resolved in the region of Somaliland, where the ratio of economic interests favors the productive sector and traditional institutions promote income sharing between groups, but not in the region of Puntland, where these conditions do not hold. The model also accounts for several of the empirical patterns in the relationships between piracy, livestock exports, and conflict in both regions. ∗We are grateful to Dawud Abdirahman, Ben Ansell, Bob Bates, Oeindrila Dube, Clare Elder, Jim Fearon, Michihiro Kandori, David Laitin, Jacob Shapiro, Takuo Sugaya, Michael Tiernay, and audiences at APSA, the Univ. of Chicago, MPSA, Oxford, the Univ. of Rochester, Stanford, and UCLA for valuable feedback. †Associate Professor of Political Science, Stanford University, Encina Hall West Rm. 406, Stanford CA 94305-6044 (email:
[email protected]). ‡Associate Professor of Government, University of Oxford, Lady Margaret Hall, Norham Gardens, Oxford OX2 6QA, UK (email:
[email protected]).