Abstract: | This article studies the optimal direct/indirect tax mix problem when individuals differ in several unobservable characteristics (productivity and endowments). It presents general expressions for the optimal commodity tax rates and proves that contrary to Atkinson and Stiglitz's (1976) result, differential commodity taxation remains a useful instrument of tax policy even if preferences are separable between labor and produced goods. When cross substitution effects are zero, the expressions resemble traditional many households Ramsey rules. In a Cobb–Douglas illustration, where endowments differ only in good 1 (interpreted as “wealth”), the tax on good 2 provides an indirect way to tax the unobservable wealth. |