Comonotonicity (''same variation'') of random variables minimizes hedging possibilities and has been widely used, e.g., in Gilboa and Schmeidler's ambiguity models. This paper investigates anticomonotonicity (''opposite variation''; abbreviated ''AC''), the natural counterpart to comonotonicity....

A key feature of communication with evidence is skepticism: a receiver will attribute any incomplete disclosure to the sender concealing unfavorable evidence. I study when a change in the receiver's prior belief about the sender's evidence induces more skepticism, i.e. induces the receiver,...

How best to incentivise disclosure? We study this question in a general model in which a technological breakthrough occurs at an uncertain time and is privately observed by an agent, and a principal must incentivise disclosure via her control of a payoff-relevant physical allocation. We uncover...

We introduce a model of probabilistic verification in mechanism design. The principal elicits a message from the agent and then selects a test to give the agent. The agent's true type determines the probability with which he can pass each test. We characterize whether each type has an associated...

Implementation theory is concerned with the existence of mechanisms in which, at each state of the world, all equilibria result in outcomes that are within a given Social Choice Correspondence (SCC). But if agents make mistakes, if their preferences or the solution concept are misspecified, or...

In repeated principal-agent problems and games, more outcomes are implementable when performance signals are privately observed by a principal or mediator with commitment power than when the same signals are publicly observed and form the basis of a recursive equilibrium. We investigate the...

We study project selection and development by a principal, interacting with two agents each of whom wants their respective project selected. When the best choice is uncertain, keeping both projects alive gives the principal the ability to adapt its choice in the future, but implies an efficiency...

This paper proves the existence of a non-stationary equilibrium in the canonical search-and-matching model with heterogeneous agents. Non-stationarity entails that the number and characteristics of unmatched agents evolve endogenously over time. An equilibrium exists under minimal regularity...

In markets with budget-constrained buyers, competitive equilibria need not be efficient in the utilitarian sense, or maximise the seller's revenue. We consider a setting with multiple divisible goods. Competitive equilibrium outcomes, and only those, are constrained utilitarian efficient, a...

A group of agents with a common prior receive informative signals about an unknown state repeatedly over time. If these signals were public, agents' beliefs would be identical and commonly known. This suggests that if signals were private, then the more correlated these are, the greater the...