Strategic Voting and Ticket-Splitting in Mixed Electoral Systems: A Finite-Mixture Approach Applied to the Case of Germany

Why voters split their votes between elections at different (state vs federal) levels or between ballots in mixed dual ballot electoral systems has been subject of a debate for several years now. A natural explanation is that ticket-splitting in mixed electoral systems is the result of various voting strategies: wasted-vote avoidance in the plurality vote on the ballot, threshold insurance in the proportional vote on the ballot, or a combination of both. Uncovering such voting strategies however has posed a considerable challenge, as they cannot be observed directly. Despite the importance of strategic voting no, consensus has yet been reached on how to measure it. The proposed paper applies a finite-mixture discrete choice model to the case of ticket-splitting in the context of the mixed electoral system of Germany. Based on the German Election studies of 2009 and 2013 it derives the proportion of ticket-splitting that can be attributed to wasted-vote avoidance, to the intention to bring about a preferred coalition, and to a combination of such considerations.