This paper studies the efficiency of competitive equilibria in environments with a moral hazard problem and unobserved states, both with retrading in ex post spot markets. The interaction between private information problems and the possibility of retrade creates an externality, unless...

This paper revisits the no-attachment assumption in job search models with random productivity fluctuations and Nash-bargaining. Both workers and firms value the option to remain in attachment: firms profit from a reduced hiring cost, while workers gain from a higher reservation wage when...

Credit constraints that link a private agent’s debt to market-determined prices embody a credit externality that drives a wedge between competitive and constrained socially optimal equilibria, inducing private agents to overborrow. The externality arises because agents fail to internalize the...

When individuals' labor and capital income are subject to uninsurable idiosyncratic risks, should capital and labor be taxed, and if so how? In a two period general equilibrium model with production, we derive a decomposition formula of the welfare effects of these taxes into insurance and...

Public provision of a private goods is justified on efficiency grounds in a model with no redistributive preferences. A government’s involvement in the provision of a private good generates information about preferences that facilitates more efficient revenue extraction for the provision of...

We consider an economy where individuals privately choose effort and trade competitively priced securities that pay off with effort-determined probability. We show that if insurance against a negative shock is sufficiently incomplete, then standard functional form restrictions ensure that...