Every agent reports his willingness to pay for one unit of a good. A mechanism allocates goods and cost shares to some agents. We characterize the group strategyproof (GSP) mechanisms under two alternative continuity conditions interpreted as tie-breaking rules. With the maximalist rule (MAX) an...

We offer complete characterizations of the equilibrium outcomes of two prominent agenda voting institutions that are widely used in the democratic world: the amendment, also known as the Anglo-American procedure, and the successive, or equivalently the Euro-Latin procedure. Our axiomatic...

We analyze the problem of a jury that must rank a set of contestants whose socially optimal ranking is common knowledge among jurors who may have friends among the contestants and may, therefore, be biased in their friends' favor. We show a natural mechanism that is finite and complete...

We consider full implementation in complete-information environments when agents have an arbitrarily small preference for honesty. We offer a condition called separable punishment and show that when it holds and there are at least two agents, any social choice function can be implemented by a...

We consider the problem of dividing a homogeneous divisible good among n players. Each player holds a private non-negative utility function that depends only on the amount of the good that he receives. We define the fair share of a player P to be the average utility that a player could receive...

We model a common pool resource game under environmental uncertainty, where individuals in a symmetric group face the dilemma of sharing a common resource. Each player chooses a consumption level and obtains a corresponding share of that resource, but if total consumption exceeds a sustainable...

We study a mechanism design problem in which players can take part in a mechanism to coordinate their actions in a default game. By refusing to participate in the mechanism, a player can revert to playing the default game non-cooperatively. We show with an example that some allocation rules are...

We study the problem of finding the profit-maximizing mechanism for a monopolistic provider of a single, non-excludable public good. Our model covers the most general setting, namely, we allow for correlation in the signal distribution as well as for informational externalities in the...

In the basic adverse selection model, a seller makes a contract offer to a privately informed buyer. A fundamental hypothesis of incentive theory is that the seller may want to offer a menu of contracts to separate the buyer types. In the good state of nature, total surplus is not different from...

An aggregation rule maps each profile of individual strict preference orderings over a set of alternatives into a social ordering over that set. We call such a rule strategy-proof if misreporting one's preference never produces a different social ordering that is between the original ordering...