Premium subsidies for health insurance: excessive coverage vs. adverse selection.

The tax subsidy for employment-related health insurance can lead to excessive coverage and excessive spending on medical care. Yet, the potential also exists for adverse selection to result in the opposite problem-insufficient coverage and underconsumption of medical care. This paper uses the model of Rothschild and Stiglitz (R-S) to show that a simple linear premium subsidy can correct market failure due to adverse selection. The optimal linear subsidy balances welfare losses from excessive coverage against welfare gains from reduced adverse selection. Indeed, a capped premium subsidy may mitigate adverse selection without creating incentives for excessive coverage.