We thank Alicia Adsera, Cevat Giray Aksoy, Alberto Alesina, Sofia Amaral, Oriana Bandiera, Samuel Bazzi, Chris Blattman, Leah Boustan, Timothy Besley, Eli Berman, Ethan Bueno de Mesquita, Filipe Campante, Doris Chiang, Abby Córdova, Raul Sanchez De la Sierra, Melissa Dell, Patricio Dominguez, John J. Donohue, Jennifer Doleac, Oeindrila Dube, Thad Dunning, Stefano Fiorin, Thomas Fujiwara, Tarek Ghani, Edward Glaeser, Jeff Grogger, Sergei Guriev, Gaurav Khanna, Asim Khwaja, Tom Kirchmaier, Ilyana Kuziemko, Horacio Larreguy, Benjamin Lessing, Nicola Limodio, Sarah Lowes, Stephen Machin, Atif Mian, Magne Mogstad, Chris Neilson, Sam Norris, Daniel Ortega, Emily Owens, Rohini Pande, Paolo Pinotti, Oscar Pocasangre, Nishith Prakash, Stephen Redding, James Robinson, Mark Rosenzweig, Matteo Sandi, Jacob Shapiro, Santiago Tobón, Daniel Treisman, Oliver Vanden Eynde, Juan Vargas, Leonard We thank five anonymous referees, Alicia Adsera, Cevat Giray Aksoy, Alberto Alesina, Sofia Amaral, Oriana Bandiera, Samuel Bazzi, Chris Blattman, Leah Boustan, Timothy Besley, Eli Berman, Ethan Bueno de Mesquita, Filipe Campante, Doris Chiang, Abby Córdova, Raul Sanchez de la Sierra, Melissa Dell, Patricio Dominguez, John J. Donohue, Jennifer Doleac, Oeindrila Dube, Thad Dunning, Stefano Fiorin, Thomas Fujiwara, Tarek Ghani, Edward Glaeser, Jeff Grogger, Sergei Guriev, Gaurav Khanna, Asim Khwaja, Tom Kirchmaier, Ilyana Kuziemko, Horacio Larreguy, Benjamin Lessing, Nicola Limodio, Sarah Lowes, Stephen Machin, Atif Mian, Magne Mogstad, Chris Neilson, Sam Norris, Ben Olken, Daniel Ortega, Emily Owens, Rohini Pande, Paolo Pinotti, Oscar Pocasangre, Nishith Prakash, Stephen Redding, James Robinson, Mark Rosenzweig, Matteo Sandi, Jacob Shapiro, Santiago Tobón, Daniel Treisman, Oliver Vanden Eynde, Juan Vargas, Leonard Wantchekon, Austin Wright, Nathaniel Young, Ekaterina Zhuravskaya, Owen Zidar, Fabrizio Zilibotti, and the participants of seminars and conferences at the AEA, AL CAPONE, APPAM, APSA, Berkeley, Bocconi, CERP, Conference on the Economics of Crime and Justice, the EBRD, ESOC, Harvard, the IDB, ifo Institute, LSE, MIT, NBER SI, PSE, Princeton, Sciences Po, University of Chicago, University of Connecticut, University of Munich, University of Passau, and Yale for helpful comments and suggestions. We also thank the International Crisis Group for helping us get access to certain parts of the data. Carlos Aguilar, Paulo Matos, Sarita Oré Quispe, Graciela Saca, and Édgar Sánchez-Cuevas provided excellent research assistance. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.