Vote trading in power-sharing systems -i.e., systems in which a voter's utility with respect to the election's outcome is proportional to the vote share of her favourite party- is, in theory, welfare improving. However, trading votes for money in majoritarian systems may have detrimental welfare...

We design the class of (indirect) Approval mechanisms which allow the players' strategies to coincide with the subsets of the outcome space. By focusing on the single-peaked domain, we prove that: a) Each of these mechanisms is characterized by a unique equilibrium outcome, and b) for almost...

We study a voting scheme for multiple alternatives. Our scheme generalizes the two-alternative quadratic voting scheme of Lalley and Weyl. We prove that our generalization results in an outcome where the most-valued alternative wins, and that the vote totals order alternatives from most-to-least...

A vote-buying mechanism is such that each agent buys a quantity of votes x to cast for an alternative of her choosing, at a cost c(x), and the outcome is determined by the total number of votes cast for each alternative. In the context of binary decisions, we prove that the choice rules that can...