We consider collective decision-making when society consists of groups endowed with voting weights. Each group chooses an internal rule that specifies the allocation of its weight to alternatives as a function of its members' preferences. Under fairly general conditions, we show that the...

We consider hybrid procedures: a first step of reducing the game by iterated elimination of weakly dominated strategies (IEWDS) followed by a second step of applying an equilibrium refinement. We show that the set of perfect/proper outcomes of a reduced normal-form game might be larger than the...

This paper provides a theoretical foundation which supports the degressive proportionality principle in apportionment problems. The core of the argument is that each individual derives utility from the fact that the collective decision matches her own will with some frequency, with marginal...

It is well known that ex post efficient mechanisms for the provision of indivisible public goods are not interim individually rational. However, the corresponding literature assumes that agents who veto a mechanism can enforce a situation in which the public good is never provided. This paper...