Suppose that the goals of a society can be summarized in a social choice rule, i.e., a mapping from relevant underlying parameters to final outcomes. Typically, the underlying parameters (e.g., individual preferences) are private information to the agents in society. The implementation problem...

This paper provides a noncooperative approach to core stability in an economy with incomplete information. The analysis covers general exchange economies, although our tightest results hold when effective coalitions consist of at most two players, as in matching. We study the perfect Bayesian...

The Nash program is an important research agenda initiated in Nash (1953) in order to bridge the gap between the noncooperative and cooperative counterparts of game theory. The program is thus turning sixty-seven years old, but I will argue it is not ready for retirement, as it is full of energy...

We view achieving a particular correlated equilibrium distribution for a normal form game as an implementation problem. We show, using a parametric version of the two-person Chicken game and a wide class of correlated equilibrium distributions, that a social choice function that chooses a...

We offer a rationalization of the weak axiom of revealed preference (WARP) and of the weak generalized axiom of revealed preference (WGARP) for both finite and infinite data sets of consumer choice. We call it maximin rationalization, in which each pairwise choice is associated with a local...

This paper investigates rationalizable implementation of social choice sets (SCSs) in incomplete information environments. We identify rationalizable incentive compatibility (RIC) as its key condition, argue by means of example that RIC is strictly weaker than the standard Bayesian incentive...

We first observe that two of Maskin's results do not extend beyond three players: we construct a four-player partition function with nonpositive externalities whose unique solution is inefficient, as well as a four-player characteristic function that has a unique efficient solution for each...

In this paper we provide two simple new versions of Arrow's impossibility theorem, in a model with only one preference profile. Both versions are transparent, requiring minimal mathematical sophistication. The first version assumes there are only two people in society, whose preferences are...