**Why is the Long-Run Tax on Capital Income Zero? Reinterpreting the Chamley-Judd Result**

Why is it optimal not to tax capital income in the long run in Chamley (1986) and Judd (1985)? This paper demonstrates that the answer follows from standard intuitions from the optimal commodity-tax literature. We show that the steady state assumption is critical for the Chamley-Judd result: in the steady-state, Engel curves for consumption become linear in labor earnings and consumption demands become equally complementary to leisure over time. From the optimal tax literature, we conclude that consumption should be taxed uniformly, which means that the optimal capital income tax is zero. We show that the intuition that capital income should not be taxed because the consumption distortions become infinite only applies when restrictions are imposed on the utility function. These restrictions ensure that consumption demands are equally complementary to leisure in the long run, thereby confirming standard optimal-tax intuitions. We also demonstrate that the optimal capital-income tax is zero irrespective of whether factor prices are determined in partial or general equilibrium. This result contradicts the intuition that optimal taxes on capital income are zero because the entire burden of capital income taxes is shifted to labor through general-equilibrium effects on factor prices.