We augment a standard tax model by concerns about tax equity: people get upset when labour is taxed more heavily than capital. Even the slightest concern for tax equity invalidates the common recommendation for small open economies that capital should remain tax-exempt. This holds for exogenous...

This paper provides general and empirically implementable sufficient statistics formulas for optimal nonlinear tax systems in the presence of across-income heterogeneity in preferences, inheritances, income-shifting capabilities, and other sources. We study unrestricted tax systems on income and...