In order to encourage entry and lower prices, most regulated markets for health insurance include policies that seek to reduce the uncertainty faced by insurers. In addition to risk adjustment of premiums paid to plans, the Health Insurance Marketplaces established by the Affordable Care Act...

Behavioral economic research has established that defaults, one form of nudge, powerfully influence choices. In most policy contexts, all individuals receive the same nudge. We present a model that analyzes the optimal universal nudge when individuals differ in their preferences, different...