Optimal dynamic nonlinear income taxation with wage regulations

We extend Stiglitz (J Public Econ, 17, 213–240,1982) to a dynamic and stochastic optimal taxation model, while assessing the effects of exogenous wage regulations. We show that when wage regulations are imposed, consumption inequality rises more than when they are removed. The results lead to an important policy implication that in the face of exogenous wage regulations, the social planner who can design optimal tax schedule prefers to widen the consumption inequality. From this perspective, the drive to enhance production efficiency outweighs the motivation for redistribution. A conventional wisdom that full employment commitment and minimum wage legislation should serve as a buffer for the minority may not be taken for granted. In the qualitative analysis, we find that as wage regulations tighten, the lower bound of the marginal tax rate on capital rises. Our quantitative result validates that, showing that the marginal tax rate on capital increases to varying degrees in response to wage requirements of varying tightness.