Is Vote Buying Effective? Evidence from a Field Experiment in West Africa


  • I thank the editor David Myatt, four anonymous referees, Abigail Barr, Robert Bates, Cátia Batista, Tim Besley, Paul Collier, Esther Duflo, Marcel Fafchamps, John Gerring, Macartan Humphreys, Asim Khwaja, Rocco Macchiavello, Casey Mulligan, Roger Myerson, Rohini Pande, Susana Peralta, Torsten Persson, Gerhard Seibert and Leonard Wantchekon for helpful suggestions. I am particularly grateful to Christian Helmers for excellent research assistance during the fieldwork. I thank participants at AEA/ASSA, NEUDC, BREAD/CEPR, ASA, APSA, EEA and CSAE conferences, and at various seminar presentations. The National Electoral Commission of São Tomé and Príncipe, through its president, José Carlos Barreiros, provided invaluable local support to this research, for which I am most indebted. I am also thankful to CPLP, namely Hélder Lucas and Leonardo Simão, for coordination with their electoral observation mission. A. Assunção, C. Castro, D. Coelho, A. Costa, A. Dias, M. Diogo, E. Lima, H. Mandinga, C. Moreno, A. Penhor and E. Solé participated in the fieldwork team: their dedication was crucial for the success of this project. I wish to acknowledge financial support from the Open Society Institute. Any errors are my responsibility.

Corresponding author: Pedro C. Vicente, Nova School of Business and Economics, Campus de Campolide, 1099-032 Lisboa, Portugal. Email:


Vote buying, i.e. cash for votes, happens frequently in many parts of the world. However, in the presence of secret ballots, there is no obvious way to enforce vote transactions. To infer effects of vote buying on electoral behaviour, I designed and conducted a randomised field experiment during an election in São Tomé and Príncipe. I follow a voter education campaign against vote buying, using panel survey measurements as well as disaggregated electoral results. Results show that the campaign reduced the influence of money offered on voting, decreased voter turnout and favoured the incumbent. This evidence suggests that vote buying increases participation and counteracts the incumbency advantage.