Assessing success and decisiveness in voting situations

In this paper we propose a simple model for measuring 'success' or 'decisiveness' in voting situations. For an assessment of these features two inputs are claimed to be necessary: the voting rule and the voters' behavior. The voting rule specifies when a proposal is to be accepted or rejected depending on the resulting vote configuration. Voting behavior is summarized by a distribution of probability over the vote configurations. This basic model provides a clear common conceptual basis for reinterpreting different power indices and some related game theoretic notions coherently from a unified point of view.