In this paper we study the quantitative impact of marginal tax rates on the distribution of income. Our methodology builds on computable general-equilibrium framework. We find that distortions from marginal tax rate changes of the sort implied by the Tax Reform Act of 1986 have sizable effects on income inequality in a reasonably quantified life-cycle setting: In our model rate changes alone capture half the increase in the pretax Gini that actually occurred between 1984 and 1989. (JEL C68, D31, H30, H20)

This paper uses a new, large-scale, dynamic life-cycle simulation model to compare the welfare and macroeconomic effects of transitions to five fundamental alternatives to the U.S. federal income tax, including a proportional consumption tax and a flat tax. The model incorporates intragenerational heterogeneity and a detailed specification of alternative tax systems. Simulation results project significant long-run increases in output for some reforms. For other reforms, namely those that seek to insulate the poor and initial older generations from adverse welfare changes, long-run output gains are modest. (JEL H20, C68)