Death spiral or euthanasia? The demise of generous group health insurance coverage.

Employers must determine the types of health care plans to offer and also set employee premiums for each plan provided. Depending on the structure of the employee share of premiums across different health insurance plans, the incentives to choose one plan over another are altered. If employees know premiums do not fully reflect the risk differences among workers, such pricing can give rise to a so-called "death spiral" due to adverse selection. This paper uses longitudinal information from a natural experiment in the management of health benefits for a large employer to explore the impact of moving from a fixed-dollar contribution policy to a partially risk-adjusted employer contribution policy. Our results show that implementing a significant risk adjustment had no discernable effect on adverse selection against the most generous indemnity insurance policy. This stands in stark contrast to previous studies, which have tended to estimate large impacts attributed to selection when employers move to a fixed-dollar policy from one with some risk adjustment. Further analysis suggests that previous studies, which appeared to detect plans in the throes of a death spiral, may instead have been reflecting an inexorable movement away from a non-preferred product, one that would have been inefficient for nearly all workers even in the absence of adverse selection.