Fighting Crime with a Little Help from my Friends: Party Affiliation, Inter-jurisdictional Cooperation and Crime in Mexico

We investigate the relationship between inter-jurisdictional cooperation and law enforcement in Mexico. Exploiting a Regression Discontinuity Design in close municipal elections, we study how improved opportunities for cooperation in crime prevention among neighboring municipalities proxied by their degree of political alignment may result in lower rates of violent crime. We find that municipalities in which the party in power in the majority of neighboring jurisdictions barely won experience significantly lower homicide rates during the mayor’s mandate than those in which it barely lost. This effect is sizeable and independent of which party is in power in the neighboring municipalities. *We thank Pedro Dal Bó, Roberto Galbiati, Emeric Henry, Brian Knight, Jens Ludwig, Cesar Martinelli and Daniel Mejía for helpful comments, and seminar participants at Universidad de Los Andes and ITAM as well as participants at the 2013 meeting of the LACEA America Latina Crime and Policy Network for helpful discussion. We are grateful to Patrick Signoret, Carlos Farah, and Etienne Fize for excellent research assistance. Ruben Durante is grateful to the Interdisciplinary Center for Public Policy Evaluation (LIEPP) at Sciences Po for financial support. †Sciences Po and Yale University. Contact: [email protected]. ‡ITAM-CIE. Contact: [email protected].