Optimal taxes on capital in the OLG model with uninsurable idiosyncratic income risk
Journal of Public Economics · 2021 · Dirk Krueger、Alexander Ludwig、Sergio Villalvazo
中文摘要
我们在一个世代交叠模型中刻画了最优线性资本税,该模型中的家庭生存两期并面临不可保险的异质性劳动收入风险。拉姆齐政府会将私人预防性储蓄对要素价格产生的一般均衡效应内部化,除非社会福利函数中赋予未来世代的权重足够高,否则会对资本征税。在对数效用下,拉姆齐问题存在完整的解析解,其最优总储蓄率与收入风险无关,而用于实现该储蓄率的最优时不变资本税则随收入风险的增加而提高。最优储蓄率在过渡路径上保持不变,其符号取决于风险的大小以及未来世代的帕累托权重。若使稳态效用最大化的拉姆齐税率为正,那么永久实施该税率将引发帕累托改进的过渡,即使初始均衡资本存量低于黄金律水平也是如此。
Abstract
We characterize the optimal linear tax on capital in an Overlapping Generations model with two period lived households facing uninsurable idiosyncratic labor income risk. The Ramsey government internalizes the general equilibrium effects of private precautionary saving on factor prices and taxes capital unless the weight on future generations in the social welfare function is sufficiently high. For logarithmic utility a complete analytical solution of the Ramsey problem exhibits an optimal aggregate saving rate that is independent of income risk, whereas the optimal time-invariant tax on capital implementing this saving rate is increasing in income risk. The optimal saving rate is constant along the transition and its sign depends on the magnitude of risk and on the Pareto weight of future generations. If the Ramsey tax rate that maximizes steady state utility is positive, then implementing this tax rate permanently induces a Pareto-improving transition even if the initial equilibrium capital stock is below the golden rule.