Implications of Efficient Risk Sharing without Commitment
研究在对称信息且无承诺的环境中，不完全风险分散何时是有效配置的特征，发现个体耐心程度决定长期最优状态，并指出历史依赖可区分缺乏承诺与其他解释。
Consumption data generally indicates that consumption risk is not perfectly diversified across individuals. This paper considers if and when imperfect diversification is a feature of efficient allocations in a symmetric information environment without commitment. It shows that if individuals are sufficiently patient, imperfect diversification is always sub-optimal in the long run; however, if individuals are not so patient, imperfect diversification is always optimal. The paper goes on to demonstrate that the way that history matters in an efficient allocation in a symmetric-information/no-commitment environment can be used to distinguish lack of commitment from other possible rationalizations of imperfect risk sharing, such as efficiency in the presence of asymmetric information.