Optimal Taxation of Entrepreneurial Capital with Private Information

This paper studies optimal taxation of entrepreneurial capital and financial assets in economies with private information. Returns to entrepreneurial capital are risky and depend on entrepreneurs’ effort, which is not observed. The presence of idiosyncratic risk in capital returns implies that constrained-efficient allocations display an intertemporal wedge on entrepreneurial capital that can be positive or negative. The properties of optimal marginal taxes on entrepreneurial capital depend on the sign of this wedge. If the wedge is positive, the marginal capital tax should be decreasing in capital returns, while the opposite is true when the wedge is negative. The optimal tax system equalizes after tax returns on all assets, thus reducing the variance of capital returns after tax relative to other assets. If entrepreneurs are allowed to sell shares of their capital to outside investors, returns to externally owned capital are subject to double taxation at the level of the entrepreneur and at the level of the outside investors. Even if entrepreneurs can purchase private insurance against their idiosyncratic risk, optimal asset taxes are essential to implement the constrained-efficient allocation if entrepreneurial portfolios are private information.