Strategic Split-Ticket Voting in Mixed Electoral Systems: The Cases of Germany, Hungary, and Lithuania

Introduction

Although researchers have extensively studied patterns of both strategic voting and split-ticket voting have in the past, they remain difficult to observe or measure and can still be considered somewhat elusive subjects in political science. At the same time, with the growing number of mixed member electoral system used around the world, the intersection of tactical and split-ticket voting provides new data for research every election year. This paper aims to examine this subject by analyzing the results of 23 legislative elections in three countries using mixed electoral systems: Germany, Hungary, and Lithuania. The main goal of this research is to further improve researchers’ understanding of the relationship between strategic voting and ticket splitting by exploring new, common quantitative measures. The three selected countries do not use identical electoral systems. Rather, their common characteristic is that they provide an opportunity for the voters to split their ballot between an individual candidate running in a single-member constituency and a party list competing on either a national or a regional level. This makes it possible to compare the two different types of votes and to search for patterns indicating strategic behavior. In this paper, the authors introduce two analytic tools: one for determining the approximate quantity of split ballots and another one for measuring strategic voting patterns based on the concentration of split tickets. The two measures rely on each other in an indirect manner, and although they analyze two separate, sometimes independent phenomena, they are both calculated based on the difference between party list and candidate vote counts. The rate of split-ticket votes provides the context for the concentration of such ballots and indicates an overlap between split voting and strategic voting.