We study a combinatorial variant of the classical principal-agent model. In our setting a principal wishes to incentivize a team of strategic agents to exert costly effort on his behalf. Agentsʼ actions are hidden and the principal observes only the outcome of the team, which depends...

We consider the problem of a spatially distributed market with strategic agents. A single good is traded in a set of independent markets, where shipment between markets is possible but costly. The problem has previously been studied in the non-strategic case, in which it can be analyzed and...

We study the equilibria of non-atomic congestion games in which there are two types of players: rational players, who seek to minimize their own delay, and malicious players, who seek to maximize the average delay experienced by the rational players. We study the existence of pure and mixed Nash...

In many economic settings, like spectrum and real-estate auctions, geometric figures on the plane are for sale. Each bidder bids for his desired figure, and the auctioneer has to choose a set of disjoint figures that maximizes the social welfare. In this work, we design mechanisms that are both...

In the presence of self-interested parties, mechanism designers typically aim to implement some social-choice function in an equilibrium. This paper studies the cost of such equilibrium requirements in terms of communication. While a certain amount of information x needs to be communicated just...

We study network games in which each player wishes to connect his source and sink, and the cost of each edge is shared among its users either equally (in Fair Connection Games--FCG's) or arbitrarily (in General Connection Games--GCG's). We study the existence and quality of strong equilibria...

A topology is efficient for network games if, for any game over it, every Nash equilibrium is socially optimal. It is well known that many topologies are not efficient for network games. We characterize efficient topologies in network games with a finite set of players, each wishing to transmit...

While traditional mechanism design typically assumes isomorphism between the agents' type- and action spaces, in many situations the agents face strict restrictions on their action space due to, e.g., technical, behavioral or regulatory reasons. We devise a general framework for the study of...

We study an economic setting in which a principal motivates a team of strategic agents to exert costly effort toward the success of a joint project. The action taken by each agent is hidden and affects the (binary) outcome of the agent's individual task stochastically. A Boolean function, called...

A strong equilibrium is a pure Nash equilibrium which is resilient to deviations by coalitions. We define the strong price of anarchy (SPoA) to be the ratio of the worst strong equilibrium to the social optimum. Differently from the Price of Anarchy (defined as the ratio of the worst Nash...