Party Activists in the 2009 German Federal Elections

Formal modelers of party competition often have to face the fact that their models predict far too centrist equilibrium positions when compared to empirically observed party positions. Various components have been suggested as extensions for the standard Downsian spatial model, in order to receive more plausible, diverging equilibrium configurations. One important improvement was the inclusion of a valence term that accounts for non-policy related factors that influence vote decisions.The underlying assumption is that valence describes an overall perceived external popularity or competence, that is ascribed to a party and/or its leader and cannot be attributed to the parties, policy position.This valence term is thus assumed to be exogenously and constant among the voters. The model can further be extended by the inclusion of an additional individual specific non-policy element, such as partisan bias or ideological distances to party positions. This stabilizes the formal game of party competition by diminishing the probability of parties leapfrogging each other in equilibrium configurations. Still, the predictions of those models show significant discrepancy to empirical party configurations.