In contexts in which players have no priors, we analyze a learning process based on ex-post regret as a guide to understand how to play games of incomplete information under private values. The conclusions depend on whether players interact within a fixed set (fixed matching) or they are...

The mechanism used in Nash implementation is a form of direct democracy, taking everyone''s opinion into account. We augment this mechanism with a political process that selects the opinions of a subset of the individuals. We study three such processes -- oligarchy, oligarchic democracy and...

Previous theoretical literature proved the existence of an upper bound on efficiency in bilateral bargaining. In contrast, experiments consistently find players obtaining higher efficiency than the upper bound if they are allowed to communicate before the 1/2-double auction. We bridge this gap...

Previous literature proved the existence of an upper bound on the probability of trade in a bilateral trading problem when the valuations are distributed uniformly on [0,1]. This upper bound is achieved in the ½-double auction when the players play the Chatterjee-Samuelson strategies. We...

We introduce trustworthy traders in bilateral trading. Trustworthy traders do not misrepresent their private information. We prove that an increase in the levels of trust (probabilities that traders are trustworthy) can reduce the maximum attainable probability of trade among the strategic...

We study a spatial model of party formation in which the set of agendas is the unit circle. We characterize the sets of pure-strategy Nash equilibria under the plurality and proportional rules. In both rules, multiple configurations of parties are possible in Nash equilibrium. We refine our...

The mechanism used in Nash implementation is a form of direct democracy, taking everyone''s opinion into account. We augment this mechanism with a political process that selects the opinions of a subset of the individuals. We study three such processes -- oligarchy, oligarchic democracy and...

We study a spatial model of party formation in which the set of agendas is the unit circle. We characterize the sets of pure-strategy Nash equilibria under the plurality and proportional rules. In both rules, multiple configurations of parties are possible in Nash equilibrium. We refine our...