Going It Alone? Strategic Entry under Mixed Electoral Rules


  • We are grateful to many people who have helped us locate, collect, or code the data and who have provided thoughtful comments on previous versions of the article. In particular, we would like to thank Barry Burden, Matt Carlson, Ron Francisco, Thomas Gschwend, Sunshine Hillygus, Mike Kellermann, Taehyun Nam, Misa Nishikawa, Susumu Shikano, Brian Silver, Christina Schenstrom, Rob Weiner, the participants in Harvard's Political Psychology and Behavior workshop, the participants in the Kolloquium at the University of Mannheim's Center for European Social Research (MZES), and the three anonymous referees. We bear responsibility for any errors and omissions.

Federico Ferrara is a Ph.D. candidate in government, Harvard University, Littauer Center, North Yard, Cambridge, MA 02138 (ferrara@fas.harvard.edu). Erik S. Herron is Assistant Professor of Political Science, University of Kansas, 1541 Lilac Lane, 310 Blake Hall, Lawrence, KS 66044-3177 (eherron@ku.edu).


Recent studies on strategic voting and entry in elections that combine plurality or majority and proportional representation (PR) have found candidate placement in single-member district (SMD) races to improve a party's PR performance. The primary implication of the existence of “contamination effects” is that parties have an incentive to nominate candidates in as many single-member districts as possible. Pre-electoral coordination in the majoritarian component of mixed electoral systems, however, is far from uncommon. In this article, we identify a number of institutional incentives that induce political parties to form pre-electoral alliances in spite of contamination effects. By identifying institutions that favor and hamper coordination, we seek to advance the understanding of PR-SMD interactions and to assess their implications for the design, classification, and empirical analysis of mixed electoral rules. Our statistical tests evaluate strategic entry in a diverse sample of countries.