This paper considers how optimal education and tax policy depends on the risk properties of human capital. It is demonstrated that a key feature of human capital investments is whether they increase or decrease wage risk. In a benchmark model it is shown that this feature alone determines whether a constrained optimal allocation should be characterized by a positive or a negative education premium. In the same model a positive intertemporal wedge is optimal. A set of generalizations, including non-observability of education, non-observability of consumption, and temporal resolution of uncertainty, are then considered to examine the robustness of these results.