We study optimal monetary and fiscal policies in a New Keynesian model with heterogeneous agents, incomplete markets, and nominal rigidities. Our approach uses small‐noise expansions and Fréchet derivatives to approximate equilibria quickly and efficiently. Responses of optimal policies to...

A ruler who does not identify with a social group, whether on religious, ethnic, cultural, or socioeconomic grounds, is confronted with a trade‐off between taking advantage of the out‐group population's eagerness to maintain its identity and inducing it to “comply” (conversion, quitting,...

The authors introduce a class of alternating-move, infinite-horizon models of duopoly. The timing captures the presence of short-run commitment s. They apply this framework to a natural monopoly in which costs are so large that at most one firm can make a profit. The firms install short-run...

The authors provide game theoretic foundations for the classic kinke d demand curve and Edgeworth cycle. In their alternating-move model, there are multiple Markov perfect equilibria of both the kinked deman d curve and Edgeworth cycle variety. In any Markov perfect equilibria , profit is...

The authors modify the standard principal-agent model with oral hazard by allowing the contract to be renegotiated after the agent's choice of action and before the observation of the action's consequences. In equilibrium, the agent randomizes over effort levels. The optimal contract gives the...

This paper studies a two-period principal/agent relationship run by short-term contracts. The principal updates the incentive scheme aft er observing the agent's first-period performance. The agent has superio r information about his ability. The principal offers a first-period incentive scheme...