Why can voters anticipate post-election coalition formation likelihoods?

A number of scholars have argued that, in contexts with multi-party governing coalitions, voters can use historical patterns to anticipate the ideological composition of likely post-election coalitions and make vote choices accordingly. In this paper we analyze historical coalition formation data from the period 1960–2007 in order to determine whether the historical regularities in the party composition of coalition governments are such that voters can use this information to assess the likelihood that different coalitions would form after an election. Specifically, we examine: (1) the likelihood of party pairs joining a coalition; (2) the likelihood of different coalition permutations; and (3) the likelihood of a party occupying the Prime Ministership.