| Abstract: | This article extends the calculus of rational voting (Riker/Ordeshook 1968) by considering the coalition building process and the legislative process (cf. Austen-Smith/Banks 1988) in multi-party systems. Comparing coalition preferences and their resulting legislative outcomes instead of party preferences, I elaborate preference profiles of voters on coalitions and estimate the probability that a coalition forms, given the parties’ coalition signals and an expected electoral result. I show the results of this rational calculus for the German Bundestag elections 2005 as a political map. Further, this calculus allows the identification of coalition signals that increase and those that reduce a party’s vote share. |
