Einy, Ezra; Haimanko, Ori - In: Games and Economic Behavior 73 (2011) 2, pp. 615-621
We show that the Shapley–Shubik power index on the domain of simple (voting) games can be uniquely characterized without the efficiency axiom. In our axiomatization, the efficiency is replaced by the following weaker requirement that we term the gain-loss axiom: any gain in power by a player...