What determines the number of political parties in a democracy? Electoral rules certainly influence the incentives to create and maintain parties. However, a society's political culture can maintain parties despite electoral rules that give them poor prospects of success. Thus, comparing the number of parties and differences in electoral rules across countries cannot clearly test the effect of the electoral rules. A better test would examine a society with a fairly continuous political culture, but a change in electoral rules. Postwar France is such a society. While the basic social order has...

Any normative theory of democracy involves notions of equity, which are supposed to guide collective decisions. On the other hand, a descriptive theory of any decision-making body must take into account the distribution of power in that body. The development of collective decision theory along two different paths reflects these two foci of interest in the theory of democracy. One direction can be subsumed under the theory of social choice, the other under the theory of games. In the theory of social choice, the participants are characterized only by their preferences among a set of...