medical insurance. We find that both the level and the shape of the distribution of risk are important in determining the … equilibrium quantity of insurance. Symmetric changes in risk (e.g., shifts in the price of medical care) better explain the … shifting insurance rate over time. Asymmetric changes (e.g., associated with a shifting age distribution) are not as important. …

This paper demonstrates the existence of adverse selection in the group insurance market with no individual choice. We … provide evidence against the “conventional wisdom” that group insurance mitigates adverse selection because of the mixture of …