Networks in Conflict: Theory and Evidence from the Great War of Africa

We study from both a theoretical and an empirical perspective how a network of military alliances and enmities affects the intensity of a conflict. The model combines elements from network theory and from the politico-economic theory of conflict. We obtain a closed-form characterization of the Nash equilibrium. Using the equilibrium conditions, we perform an empirical analysis using data on the Second Congo War, a conflict that involves many groups in a complex network of informal alliances and rivalries. The estimates of the fighting externalities are then used to infer the extent to which the conflict intensity can be reduced through (i) dismantling specific fighting groups involved in the conflict; (ii) weapon embargoes; (iii) interventions aimed at pacifying animosity among groups. Finally, with the aid of a random utility model, we study how policy shocks can induce a reshaping of the network structure. We would like to thank Valentin Muller, Sebastian Ottinger, André Python, Timo Schaefer, Matthias Schief, Nathan Zorzi, and Laura Zwyssig for excellent research assistance. We are grateful for helpful comments to the editor, five anonymous referees, Daron Acemoglu, Jerome Adda, Alberto Alesina, Alessandra Casella, Ernesto Dal Bo, Melissa Dell, Rachel Griffith, David Hemous, Macartan Humphreys, Massimo Morelli, Benjamin Olken, Maŕıa Sáez Mart́ı, Uwe Sunde, Chris Udry, Fernando Vega Redondo, Jean-Marc Robin, David Yanagizawa-Drott, and Giulio Zanella. We owe a special thanks to Rafael Lalive for his generous help on an important coding issue discussed in the paper. We also thank conference and seminar participants at ENCORE, ESEM-Asian Meeting, IEA World Congress, INFER, LLN, NBER Summer Institute, Workshop on the Economics of Organized Crime, and at the universities of Aalto, Bocconi, Bologna, CERGE-EI, Cattolica del Sacro Cuore, Chicago, Columbia, ECARES, Ecole Polytechnique, European University Institute, Geneva, Harvard/MIT, HKU, IAE-Barcelona, IIES, IMT, INSEAD, IRES, Keio, Lausanne, LSE, Luxembourg, Manchester, Marseille-Aix, Munich, Nottingham, NYU Abu Dhabi, Oxford, Oslo, Pompeu Fabra, SAET, SciencesPo Paris, Southampton, St. Gallen, Toulouse, ULB, and USI-Lugano. Mathias Thoenig acknowledges financial support from the ERC Starting Grant GRIEVANCES-313327. Dominic Rohner gratefully acknowledges funding from the Swiss National Fund grant 100017 150159 on “Ethnic Conflict.” Michael König and Fabrizio Zilibotti acknowledge financial support from the Swiss National Science Foundation through the research grant 100018 140266, and Michael König further acknowledges financial support from the Swiss National Science Foundation grant PZ00P1 154957 / 1. Department of Economics, University of Zurich. Email: [email protected]. Department of Economics, University of Lausanne. Email: [email protected]. Department of Economics, University of Lausanne. Email: [email protected]. Department of Economics, Yale University. Email: [email protected].