Explaining party ideological stances: from simulation to real elections. A comparative analysis using CSES survey data

According to the literature, three main reasons can help to explain the ideological stance assumed by a party during a given electoral competition. First, a party can decide to select a given (policy) position because he thinks that this will grant him the largest share of votes. Alternatively, he could try to assume a position that maximizes his chances to be involved in the next coalition-cabinet. Finally, he could simply select the position closest to his own ideal policy position. To discern the relative merits of these three possible sources of behaviors, one should need to contrast a number of cases, possibly characterized by different political and institutional variables, against a clear benchmark of party-behavior. This is what we do. On one side, we rely on survey-data from the CSES (Comparative Study of Electoral Systems) project up to the most recent "Advance Release" of CSES Module 3. This allows us to collect a considerable large pool of observations, covering 35 democracies and 73 elections. On the other side, following the theoretical contribution originally proposed in Adams, Grofman and Merrill (2005), we run a number of simulated scenarios, through an original script that we have developed in R, assuming that parties are mainly interested in vote-maximizing. The equilibrium party policy positions so derived constitute our counterfactual scenario against which the actual (perceived) position of parties are compared with. We use the counterfactual scenarios as proto-theoretical devices (Axelrod 1997). The aim of the comparison is to understand the nature of the electoral incentives facing parties, to explore if there are some affinities/divergences between the two moments (the actual and the simulated ones), and deriving from this some insights on real party system competition.