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...

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...

We analyze the ex ante incentive compatible core for replicated private information economies. We show that any allocation in the core when the economy is replicated sufficiently often is approximately Walrasian for the associated Arrow-Debreu economy.