Probabilistic measures of a priori voting power are useful tools to assess actors' influence on collective decision-making either for the purpose of designing a voting organ or to model particular policy cases. This paper makes an attempt to reduce a dynamic voting process into a cooperative...

This paper addresses the following issue: If a set of agents bargain on a set of feasible alternatives 'in the shadow' of a voting rule, that is, any agreement can be enforced if a 'winning coalition' supports it, what general agreements are likely to arise? In other words: What influence can...

This paper focuses on the probabilistic point of view and proposes a extremely simple probabilistic model that provides a single and simple story to account for several extensions of the Shapley value, as weighted Shapley values, semivalues, and weak (weighted or not) semivalues, and the Shapley...

We provide a new axiomatization of the Shapley-Shubik and the Banzhaf power indices in thedomain of simple superadditive games by means of transparent axioms. Only anonymity isshared with the former characterizations in the literature. The rest of the axioms are substitutedby more transparent...

In this paper we measure the effect of the quota on the difficulty of making decisions in the EU-25 Council after the next enlargement. We compute the probability of a proposal being rejected in the Council. This probability depends on the voting rule (and therefore on the quota) and on the...

Committees are often made up of representatives of different-sized groups of individuals, and make decisions by means of a voting rule which specifies what vote configurations can pass a decision. This raises the question of the choice of the optimal voting rule, given the different sizes of the...

This paper connects two notions: Hart and Mas-Colell’s ‘potential’, related to the value of coalitional games, and Coleman’s earlier notion of ‘power of a collectivity to act’, related to the easiness to make decisions by means of a voting rule. Copyright...

The semivalues (as well as the least square values) propose different linear solutions for cooperative games with transferable utility. As a byproduct, they also induce a ranking of the players. So far, no systematic analysis has studied to which extent these rankings could vary for different...