Although there are well-developed theories of two-party competition in a one-dimensional policy space, it has proven extremely difficult to construct a model of multi-party competition (with three or more parties) in two or more dimensions. One difficulty with developing such a model is due to the phenomenon of political uncertainty over the expected nature of the governing coalition. A cooperative equilibrium notion, the `political heart', is used here to characterise post-election coalition formation. Empirical evidence from 12 European political systems in the post-war period is presented, to corroborate this equilibrium concept. Using this notion, a typology based on fragmentation and centrality is proposed. A model of multi-party competition over pre-election policy proposals is described. It is argued that this model is compatible with the predictions of the political heart concerning coalition formation.
