In the preceding chapter we made a determined attempt to derive testable empirical implications from our model of government formation and to evaluate these using data on actual government formations in 12 postwar European democracies. We found considerable empirical support for our approach. Many of the implications we derived – in particular those dealing with the cabinet membership of very strong and merely strong parties – give the analyst a massive improvement over chance in making forecasts about the allocation of cabinet portfolios. In this chapter we extend our empirical analysis in three substantive directions, using more powerful statistical techniques.

The substantive extensions of our empirical analysis are concerned with two important features of the strategic position of any legislative party in the government formation process – its size and its position in the policy space. In Chapter 5 we investigated the relationship between size, policy, and strong-party status in large numbers of simulated legislatures. In the present chapter, we investigate this relationship in real legislatures. We have three key objectives in this phase of the analysis. First, we know from Chapter 5 that, in simulated legislatures, strength is strongly related both to the weight of parties and to their position in the policy space. Larger parties, and parties at a median position on at least one policy dimension, are far more likely to be strong or very strong in our simulations. We noted when reporting these simulations that party positions in real party systems are not randomly located; in this chapter we assess the extent to which a party's strength is related to its weight and policy position in the real world.