A long tradition suggests a fundamental distinction between situations of risk, where true objective probabilities are known, and unmeasurable uncertainties where no such probabilities are given. This distinction can be captured in a Bayesian model where uncertainty is represented by the agent's...

Predictions under common knowledge of payoffs may differ from those under arbitrarily, but finitely, many orders of mutual knowledge; Rubinstein's (1989)Email game is a seminal example. Weinstein and Yildiz (2007) showed that the discontinuity in the example generalizes: for all types with...

Dispersion in retail prices of identical goods is inconsistent with the standard model of price competition among identical firms, which predicts that all prices will be driven down to cost. One common explanation for such dispersion is the use of a loss-leader strategy, in which a firm prices...

In the reputation literature, players have \emph{commitment types} which represent the possibility that they do not have standard payoffs but instead are constrained to follow a particular plan. In this paper, we show that arbitrary commitment types can emerge from incomplete information about...

We develop a model of undescribable events. Examples of events that are well understood by economic agents but are prohibitively difficult to describe in advance abound in real-life. This notion has also pervaded a substantial amount of economic literature. We put forth a model of such events...

The paper develops a new modeling framework to study factor structures and Arbitrage Pricing Theory in large asset markets. The asset economy in this framework consists of a continuum of assets. Finite subsets of assets are interpreted as random draws from the underlying economy. I show that the...

The paper studies a contracting problem in which a Principal enters in two-sided moral hazards with N independent agents. There are no technological or informational linkages between the N agency problems: The Principal's costs are additive across agents; there is no common uncertainty in the...

A player inuences a collective outcome if his actions can change the probability of that outcome. He is Æ-pivotal if this change exceeds some threshold Æ. We study inuence in general environments with N players and arbitrary sets of signals. It is shown that inuence is maximized when players'...

: The paper provides a model where authority relationships are founded on reputation. The viability of authority is the result of subordinates' free-riding on each other challenges, reducing the frequency of challenges, and making reputations worth defending. The party with authority secures...