Coalitions and Government Formation: An Empirically Relevant Theory

Traditional theories of government coalition formation concentrate on formal criteria inspired by – if not directly drawn from – game theory. One such criterion is that the coalition which forms must be winning; another is that it should have no surplus members without whom it would still be winning, i.e. it should be minimal; and a third is that the number of parties should be as few as possible. The closest that such theories come to considering the substantive issues affecting the formation of coalitions in the real world is their focus on reducing the ideological diversity of parties within the government. On many occasions, however, such ideological considerations receive negligible attention from politicians, who often ignore size factors altogether.