摘要：This paper develops an elegant model on a relevant issue. The issue is a specific market failure—the lack of inflation-indexed debt— which, combined with real output uncertainty, precludes optimal risk sharing among consumers hit by idiosyncratic shocks. The paper starts with a benchmark two-period consumption and risk-sharing model under complete markets for a closed economy where agents are hit by idiosyncratic output shocks. By trading state-contingent Arrow-Debreu assets, idiosyncratic risk is completely traded away and the economy attains the first-best Pareto-optimal general equilibrium. This model follows closely the world asset trading model due to Lucas (1982) (nicely presented in chapter 5 of Obstfeld and Rogoff 1996), where two countries hit by idiosyncratic output shocks engage in first-best international exchange of state-contingent Arrow-Debreu assets.
