Optimal taxation under regional inequality

We study how regional productivity differences and labor mobility shape optimal Mirrleesian tax-transfer schemes. When tax schedules are not allowed to differ across regions, productivity-enhancing interregional migration exerts a downward pressure on optimal marginal tax rates. When regionally differentiated taxation is allowed, marginal tax rates in high-(low-)productivity regions should be corrected downwards (upwards) relative to the benchmark without migration. Simulations of the productivity differences between metropolitan and other areas of the US indicate that migration affects the optimal tax-transfer schedule more strongly in the regionally differentiated rather than in the undifferentiated case.