Coalition Formation in Non-Democracies
研究非民主社会中统治联盟的形成，提出公理方法和动态博弈模型，揭示联盟自我执行的条件，并刻画统治联盟的结构特征。
We study the formation of a ruling coalition in nondemocratic societies where institutions do not enable political commitments. Each individual is endowed with a level of political power. The ruling coalition consists of a subset of the individuals in the society and decides the distribution of resources. A ruling coalition needs to contain enough powerful members to win against any alternative coalition that may challenge it and it needs to be self-enforcing, in the sense that none of its subcoalitions should be able to secede and become the new ruling coalition. We present both an axiomatic approach that captures these notions and determines a (generically) unique ruling coalition and the analysis of a dynamic game of coalition formation that encompasses these ideas. We establish that the subgame perfect equilibria of the coalition formation game coincide with the set of ruling coalitions resulting from the axiomatic approach. A key insight of our analysis is that a coalition is made self-enforcing by the failure of its winning subcoalitions to be self-enforcing. This is most simply illustrated by the following example: with “majority rule, ” two-person coalitions are generically not self-enforcing and consequently, three-person coalitions are self-enforcing (unless one player is disproportionately powerful). We also characterize the structure of ruling coalitions. For example, we determine the conditions under which ruling coalitions