Explaining Party Ideological Stances : From Simulation to Real Elections

By relying on survey-data from the CSES (Comparative Study of Electoral Systems) project, we run a number of simulated scenarios assuming that parties are interested in vote-maximizing, and we compute for each election the distribution of party ideological positions that corresponds to a Nash Equilibrium along a one-dimensional space. This is accomplished with the help of an original package that we have developed in R that implements Merill and Adams (2001) iterative algorithm. Through that it becomes possible to evaluate in a systematic way which are the factors that can push parties toward a more centrifugal (i.e., extreme) positions in equilibrium. Secondly, we show how the equilibrium positions so derived can become a counterfactual scenario against which contrasting the actual (perceived) position of parties. The aim of the comparison is to understand the nature of the electoral incentives facing parties, and deriving insights on real party system competition