Spatial Models of Party Competition Applied

Research question/goal: 

An application of spatial models of party competition presupposes the construction of policy spaces which encompass the important policy issues of an election. These are the basis of policy voting by the electorate and of strategic position taking by parties. In addition to policy voting, individual vote functions have to include party valences and long-term commitments of voters to parties. After having estimated such vote functions for several Bundestag elections, our aim is to study equilibrium dynamics of party competition under the impact of mixed electoral systems. For pure electoral systems the folk wisdom is that first past the post induces centripetal party movements, and proportional representation induces centrifugal positioning, especially of low-valence parties. Our research question is how voters respond  to the opportunity to cast two ballots and how parties come to terms with the possibly differing equilibrium dynamics of mixed-member electoral systems.

Current stage: 

We analyse the German mixed-member electoral system by applying a neo-downsian model of party competition. Unfolding party thermometer questions recovers the two elements of the neo-downsian model: a left-right dimension and a valence dimension deduced from performance evaluations of parties. The plurality segment representation of German MPs (ratio of directly elected MPs of a party compared to all directly elected MPs) does react more to valence differences between national parties than proportional representation (ratio of all party MPs to all MPs). High valence constituency candidates of the German mixed system have the same incentive to place themselves close to the mean voter as found for pure plurality systems, whereas overall we observe more centrifugal incentives as expected for pure proportional systems.

Fact sheet

2012 to 2019
Data Sources: 
German Bundestag election surveys since 1980
Geographic Space: 



Kurella, Anna-Sophie (2017): Issue Voting and Party Competition. The Impact of Cleavage Lines on German Elections between 1980-1994. Cham: Springer. [Contributions to Political Science] more