The often heard call for other forms of democracy than the adversarial type is not realistic. MWCs and MSCs offer a peaceful mechanism for voting to handle social conflicts by means of political parties under the constraints of rule of law and the principal-agent interaction. Switzerland is the only consociational state today, but operating under heavy referenda restraints.

As political power tends to be wielded in the form of voting power in the national assembly, especially under the institutions of party government, one needs a method to calculate the voting power of political parties, both longitudinally and for a cross-section of European democracies. This paper suggests such a method, derived from the power index approach in cooperative game theory. The application of the method on the history of democracy in the two German nations results in party scores-mandates, ex ante and ex post voting power-that are much in congruence with the standard interpretations of the interwar period and the post-war politics in these two countries.

Based on the Banzhaf-Coleman approach to the analysis of political power, this article presents a new analysis of government coalitions. The party systems and types of government formation in Germany and Austria can be compared over time in a new systematic way from 1920. The findings support the theory of democratic stability that emphasizes the power balance between the major right-and left-wing groups in the party system. It can be achieved either by power alternation or through consociationalism.Keywords: party government, coalitions in Germany and Austria, the power index approach, ex ante and ex post power, power imbalance between the left and right wing parties, political stability, Banzhaf numbers.