Optimal Social Insurance with Linear Income Taxation*
研究了在存在线性所得税时，旨在保障残疾风险的最优社会保险，发现最优残疾保险金随前期收入增加，且即使残疾风险外生可验证、不存在道德风险，不完全保险仍是最优的，因为它激励工人通过更多工作和储蓄来自我保障，从而减轻再分配所得税对劳动供给和储蓄的扭曲影响。
Abstract We study optimal social insurance aimed at insuring disability risk in the presence of linear income taxation. Optimal disability insurance benefits rise with previous earnings. Optimal insurance is incomplete even though disability risks are exogenous and verifiable so that moral hazard in disability insurance is absent. Imperfect insurance is optimal because it encourages workers to insure themselves against disability by working and saving more, thereby alleviating the distortionary impact of the redistributive income tax on labor supply and savings.