Optimal Taxation and Social Insurance with Endogenous Private Insurance
研究了当私人部门提供部分保险时，政府干预的福利收益，推导出利用现有实证估计来预测最优政策的公式，并应用于健康保险和失业保险，发现正式私人保险会显著降低最优政府给付水平。
We characterize welfare gains from government intervention when the private sector provides partial insurance. We analyze models in which adverse selection, pre-existing information, or imperfect optimization create a role for government intervention. We derive formulas that map existing empirical estimates into quantitative predictions for optimal policy. When private insurance generates moral hazard, standard formulas for optimal government insurance must be modified to account for fiscal externalities. In contrast, standard formulas are unaffected by “informal” private insurance that does not generate moral hazard. Applications to health and unemployment show that formal private market insurance can significantly reduce optimal government benefit rates.