Because inputs are scarce, marginal cost should be an increasing function of output. Without changes in this real marginal cost schedule, aggregate output can vary if and only if the markup of price over marginal cost varies. In this review, we discuss the extent to which observed fluctuations...

This paper illustrates how fluctuations in aggregate economic activity can result from many small, independent shocks to individual sectors. The effects of the small independent shocks fail to cancel in the aggregate due to the presence of two non-standard assumptions: local interaction between...

The paper presents an intertemporal general equilibrium model with rationing in the product market, in which stationary sunspot equilibria are shown to exist, indicating the possibility of fluctuations in economic activity simply due to self-fulfilling variations in economic agents'...

The paper considers optimal monetary stabilization policy in a forward-looking model, when the central bank recognizes that private-sector expectations need not be precisely model-consistent, and wishes to choose a policy that will be as good as possible in the case of any beliefs that are close...

This paper proves a certainty equivalence result for optimal policy under commitment with symmetric partial information about the state of the economy in a model with forward-looking variables. This result is used in our previous paper, Indicator Variables for Optimal Policy,' which synthesizes...

In this paper we calculate robustly optimal monetary policy rules for several variants of a simple optimizing model of the monetary transmission mechanism with sticky prices and/or wages. We discuss representations of optimal policy both in terms of interest-rate feedback rules that generalize...

This paper proposes a general method for deriving an optimal monetary policy rule in the case of a dynamic linear rational-expectations model and a quadratic objective function for policy. A commitment to a rule of the type proposed results in a determinate equilibrium in which the responses to...

This paper reconsiders the Phelps-Lucas hypothesis, according to which temporary real effects of purely nominal disturbances result from imperfect information, but departs from the assumptions of Lucas (1973) in two crucial respects. Due to monopolistically competitive pricing, higher-order...