Risk Adjustment for Health Insurance: Theory and Implications

This paper explores the potential for welfare-improving public risk adjustment in health insurance markets characterized by adverse selection. The optimal risk adjustment system is derived in a theoretical model under a range of assumptions regarding government information and market equilibrium. Special attention is focused on the interaction between risk adjustment and the private transfers that can occur in markets characterized by adverse selection. Risk adjustment has the potential to improve both equity and efficiency; however, it can also have the effect of crowding out private transfers.