By defining the choices available for citizens to choose from, the structure of a country''s party system can influence whether or not its citizens turn out to vote. In previous work, scholars studying voter turnout have used the number of parties as a proxy to represent all the components of the party system, but this approach has led to inconsistent and seemingly inexplicable empirical results. The proposed study considers two additional components related to the spatial arrangement of the parties via the voter: (1) proximity of the closest party, or parties, to the voter''s ideal point and (2) relative distance between the two closest parties. To date, scholars'' explanations of voter turnout across countries tend either to ignore or pay little attention to how these latter two party system characteristics affect people''s decisions whether or not to vote. This dissertation seeks to identify how each of the party system characteristics, as well as the three in combination, influence turnout. To test the effects of these characteristics, this investigation will use an experimental design to manipulate each of the three party system characteristics to determine their independent and joint effects. The participants for the experiments will be US citizens from a large metropolitan area in the Midwest. Each participant will be asked to answer several survey questions and participate in a mock election. Based on the turnout in this mock election across the experimental conditions, the goal is to make generalizations about the effect of the party system on turnout. If successful, this study has the potential to have an important impact on the field. First, by demonstrating the independent effects of these three distinct components of the party system on turnout, scholars will have a more comprehensive understanding of how the party system affects turnout, and thus, will have a greater understanding of turnout in general. Second, experiments have the potential to greatly improve the internal validity of comparative political research. The successful use of an experimental design in this study may encourage other comparative political scientists to use experiments in their own research. Scholars could even use this design as a template for future research interested in explaining how other institutional variables affect voter turnout.
