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 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 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 investigate the problem of Nash implementation in the presence of “partially honest” individuals. A partially honest player is one who has a strict preference for revealing the true state over lying when truthtelling does not lead to a worse outcome than that which obtains when lying. We...

Sortition is the process of selecting decision makers or senators by a lottery. We introduce sortition in implementation theory by augmenting a mechanism with a kleroterion or lottery machine p that selects the senators. An outcome is implemented after consulting only the opinions of the...

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...

We address the common scenario where a group of agents wants to divide a set of items fairly, and at the same time seeks to optimize a global goal. Suppose that each item is a task and we want to find an allocation that minimizes the completion time of the last task in an envy-free manner, where...

A group of heterogeneous agents may form partnerships in pairs. All single agents as well as all partnerships generate values. If two agents choose to cooperate, they need to specify how to split their joint value among one another. In equilibrium, which may or may not exist, no agents have...

In a game of common interest there is one action vector that all players prefer to every other. Yet there may be multiple Pareto-ranked Nash equilibria in the game and the “coordination problem” refers to the fact that rational equilibrium play cannot rule out Pareto-dominated equilibria. In...

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...