This note studies the problem of implementing social choice correspondences in environments where individuals have doubts about the rationality of their opponents. We postulate the concept of "-minimax regret as our solution concept and show that social choice correspondences that are Maskin...

We study the repeated implementation of social choice functions in environments with complete information and changing preferences. We define dynamic monotonicity, a natural but nontrivial dynamic extension of Maskin monotonicity, and show that it is necessary and almost sufficient for repeated...

We study the repeated implementation of social choice functions in environments with complete information and changing preferences. We de?ne dynamic mono- tonicity, a natural but nontrivial dynamic extension of Maskin monotonicity, and show that it is necessary and almost suf?cient for repeated...

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 at that preference profile. This definition generalizes Maskin’s definition...

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...

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...