In a multiple-good risk-sharing environment with ex post private information, conditions are found under which collateralized debt is the optimal contract. The necessary and sufficient condition is that the borrower values the collateral good more highly than does the lender; otherwise the...

This Paper studies a general equilibrium economy in which agents have the ability to invest in a risky technology. The investment risk cannot be fully insured with optimal contracts because shocks are private information. We show that the presence of investment risks leads to under-accumulation...

We study a cost allocation problem under asymmetric information, and show that the ex ante incentive compatible core is non-empty. We also obtain a non-emptiness result for the incentive compatible coarse core, which is one concept of an interim core.

The rational expectations equilibrium (REE), as introduced in Radner (1979) in a general equilibrium setting à la Arrow–Debreu–McKenzie, often fails to have desirable properties such as universal existence, incentive compatibility and efficiency. We resolve those problems by providing a new...