Participation and Competition in Top-Two Elections: Trade-Offs in Election Reform

Abstract American states continue to experiment with new forms of electoral institutions, including various nonpartisan election systems. One such rule, the “top-two” procedure, allows all voters to choose any candidate in the primary, advancing whichever two candidates obtain the most votes to the general election. These general elections may feature two candidates of the same party. This paper uses data from California, the largest state to adopt this rule, to examine participation and competition in the last five elections before the top-two procedure (2002 to 2010) and the first five after it (2012 to 2020), investigating the potential trade-off between the roll-off and increased competition. We find that while roll-off occurs with copartisan elections, the compensating increases in competition are substantial. Furthermore, with this system, the meaningful competition shifts toward the higher turnout general elections, which calls into question whether there is much of a participatory cost at all. Additionally, we leverage the unusual cases of write-in candidates to illustrate the electoral dynamics of these elections, highlighting the difficulty of implementing accountability with cross-party elections while demonstrating the behavioral potential of copartisan elections.