We examine the informal exchange of favors in societies such that any two individuals interact too infrequently to sustain exchange, but such that the social pressure of the possible loss of multiple relationships can sustain exchange. Patterns of exchange that are locally enforceable and...

We prove that for any equilibrium of a (Bayesian) game, and any sequence of perturbations of that game, there exists a corresponding sequence of ex-ante ε-equilibria converging to the given equilibrium of the original game. We strengthen the conclusion to show that the approaching equilibria...

In this paper, we provide an explanation for why committees may behave over-cautiously. A committee of experts must decide whether to approve or reject a proposed innovation on behalf of "society." Each expert's private signal is a noisy version of what the "state of the art science" would...

It has long been established in the literature that the set of pure strategy Nash equilibria of any binary game of strategic complements among a set N of players can be seen as a lattice on the set of all subsets of N under the partial order defined by the set inclusion relation (⊆). If the...

We provide an explanation for why committees may behave over-cautiously. A committee of experts makes a decision on a proposed innovation on behalf of 'society'. Each expert's signal about the innovation's quality is generated by the available evidence and the best practices of the experts'...