How Well Does the U.S. Social Insurance System Provide Social Insurance?
分析了美国社会保障和所得税体系在个体面临私人观察的工资率冲击时提供的保险效果，比较了两种改革方案：优化社保福利函数和用终生收入最优税替代整个社保体系。
We analyze the insurance provided by the U.S. social security and income tax system within a model in which agents receive idiosyncratic, wage rate shocks that are privately observed. We consider two reforms: a piecemeal reform that optimally chooses the social security benefit function and a radical reform that eliminates the entire social insurance system and replaces it with an optimal tax on lifetime earnings. The radical reform outperforms the piecemeal reform and achieves nearly all of the maximum possible welfare gain when wages differ permanently over the lifetime. When wage shocks match properties in U.S. data, the piecemeal reform outperforms the radical reform. (c) 2010 by The University of Chicago. All rights reserved.