We study the gains from trade in a model with endogenously variable markups. We show that the pro-competitive gains from trade are large if the economy is characterized by (i) extensive misallocation, i.e., large ineciencies associated with markups, and (ii) a weak pattern of cross-country...

A mechanism implements a social choice correspondence f in mixed Nash equilibrium if, at any preference profile, the set of all (pure and mixed) Nash equilibrium outcomes coincides with the set of f-optimal alternatives for all cardinal representations of the preference profile. Unlike Maskinʼs...

A mechanism implements a social choice correspondence f in mixed Nash equilibrium if at any preference profile, the set of all pure and mixed Nash equilibrium outcomes coincides with the set of f-optimal alternatives at that preference profile. This definition generalizes Maskin’s definition...

This paper studies the impact of the governance of a group, whether be it unanimity, simple majority or qualified majority, on its (endogenously derived) size, composition, and inclination to change the status quo. Somewhat surprisingly, we show that not only unanimity might favor the formation...

Homo Strategicus populates the vast plains of Game Theory. He knows all logical implications of his knowledge (logical omniscience) and chooses optimal strategies given his knowledge and beliefs (rationality). This paper investigates the extent to which the logical capabilities of Homo Sapiens...

This paper introduces the concept of ordient for binary relations (preferences), a relative of the concept of gradients for functions (utilities). The lexicographic order, albeit not representable, has an ordient. Not only binary relations representable by differentiable functions have an...

This paper introduces a new solution concept, a minimax regret equilibrium, which allows for the possibility that players are uncertain about the rationality and conjectures of their opponents. We provide several applications of our concept. In particular, we consider pricesetting environments...

This paper characterizes the class of communication networks for which, in any environment (utilities and beliefs), every incentive-compatible social choice function is (partially) implementable. Among others, in environments with either common and independent beliefs and private values or a bad...

We consider non-cooperative environments in which two players have the power to commit but cannot sign binding agreements. We show that by committing to a set of actions rather than to a single action, players can implement a wide range of action profiles. We give a complete characterization of...

This paper studies the impact of the governance of a group, whether be it unanimity, simple majority or qualified majority, on its size, composition, and inclination to change the status quo. Somewhat surprisingly, we show that not only unanimity might favor the formation of larger groups than...