The Political Costs of Cross-Block Coalitions

While our knowledge about coalition formation processes and the allocation of portfolio’s within coalition governments is well developed, the literature offers little insight on how voters evaluate the performance of individual parties in different types of coalition governments. Furthermore, we also lack a precise understanding of how the policies enacted by a coalition government influence people’s vote intentions. This paper hypothesizes, that “cross block coalitions”, i.e. coalitions between parties from different political blocks, increase the probability that people vote for parties situated at the fringes of the political spectrum. The paper examines two mechanisms why this is the case: The first suggests that, on average, voters oppose coalitions that encompass different political blocks and favor within block coalitions. The second focuses on a policy-based explanation of people’s vote intention and proposes that voters approve of a cross-block coalition if the coalition delivers on their preferred policies. More specifically, I would expect the support for a leftist party in a grand coalition to remain high among leftist voters if the party delivers on policy-dimensions that are generally associated with leftist policymaking (and vice versa). However, since only one party can implement its preferred policy the other will lose votes. The paper tests this argument using data from a population based online survey experiment fielded in Germany.