Spatial theories of voting are loaded with two assumptions that empirically do not necessarily hold. The first one links to its basic idea that citizens vote for the party that would best serve their preferences. What is mostly neglected is the level of information and cognitive capacities that are necessary for this idealized rational voting. To compare parties’ political (or ideological) positions with one another and to one’s own preferences can be very demanding, especially in multiparty settings. The second problematic assumption of spatial voting theory is that it takes political positions for granted as if they were static. This might be due to the spatial model of party competition that explains why, in the long run, parties take equilibria positions that will remain stable over time. Empirically, we can, however, observe that parties’ electoral competition does lead to position dynamics, especially if new parties become competitive players. This is the truer for young party systems where the party competition space and position taking is not that settled, yet. It is hence interesting to ask what happens with voters’ perceptions and preferences after parties have shifted positions, a question that has been overlooked at large by research on voting behavior. My thesis contributes to filling this gap of research, bridging insights from the political competition and the spatial, “rational” voting literature. I argue that voters need a good level of political sophistication to keep updated on party positions and take “rational” voting decisions. Using survey data from the Comparative Study of Electoral Systems (CSES) and data on parties’ left-right positions (Franzmann and Kaiser 2006; 2016), based on the Party Manifesto Project (CMP) (Volkens 2013), I investigate parties’ position shifts’ impact on voters’ perceptions of left-right positions, how different kinds of political sophistication, factual knowledge, the differentiation between parties’ left-right positions and the precision of perceptions, determine citizens’ electoral participation, and if the precision of left-right perceptions increases rational reactions to parties’ position’ shifts. Overall, the thesis shows that single parties’ position shifts can increase the precision with which voters perceive party positions, but the stronger multiple parties shift in sum, it is hard for voters to keep updated. Voters’ often limited perceptions of parties’ positions and voters’ party loyalties are key answers to why they often seemingly do not react to parties’ shifts with “rational” voting
