The representative agent theory of asset pricing is modified to incorporate heterogeneous agents and incomplete markets. The model features two types of agents who differ up to a nontradable, idiosyncratic component in their endowment processes. Numerical solutions indicate that individuals are...

Forward and spot exchange rates between major currencies imply large standard deviations of both predictable returns from currency speculation and of the equilibrium price measure (the intertemporal marginal rate of substitution). Representative agent theory with time-additive preferences cannot...

The paper investigates portfolio strategies and derivative market making when the trader does not know the correct model. One of the puzzles from last summer's LTCM collapse was that when the Russian government defaulted, liquidity dried up. Antidotal evidence suggests that people were unable to...

We inject aggregate uncertainty - risk and ambiguity - into an otherwise standard business cycle model and describe its consequences. We find that increases in uncertainty generally reduce consumption, but they do not account, in this model, for either the magnitude or the persistence of the...

that central banks incur for implementing Taylor rule type policies.

Identification problems arise naturally in forward-looking models when agents observe more than economists. We illustrate the problem in several macro-finance models with Taylor rules. When the shock to the rule is observed by agents but not economists, identification of the rule's parameters...

We provide a user's guide to exotic' preferences: nonlinear time aggregators, departures from expected utility, preferences over time with known and unknown probabilities, risk-sensitive and robust control, hyperbolic' discounting, and preferences over sets ( temptations'). We apply each to a...