Should Marginal Tax Rates be Equalized Through Time?
推导了最优税率在时间上均等化的充要条件，发现工资税在劳动供给弹性高或风险厌恶低时应降低，资本税在预期不完美或风险厌恶变化时需调整。
I derive necessary and sufficient conditions for the intertemporal equalization of optimal tax rates. The conditions in the case of wage taxes include constant-elasticity labor supply and constant relative risk aversion. Wage taxes should be low in times of relatively elastic labor supply, or low risk aversion. The conditions in the case of capital taxes include perfect-foresight expectations and constant relative risk aversion. If foresight is imperfect, intertemporal equality will be impeded by a covariance term; if relative risk aversion is time-varying, next period's capital tax should have the same sign as this period's change in relative risk aversion.