Public investment and the risk premium for equity

Analysis of the equity premium puzzle has focused on private-sector capital markets. However, the existence of an anomalous equity premium raises important issues in the evaluation of public-sector investment projects. These issues are explored below. We begin by formalizing the argument that an equity premium may arise from uninsurable systematic risk in labour income, and show that, other things being equal, increases in public ownership of equity will improve welfare, up to the point where the equity premium is eliminated. Finally, we consider policy implications and the optimal extent of public ownership.