To design premium subsidies in a health insurance market it is necessary to estimate consumer demand, cost, and study how different subsidy schemes affect insurers' incentives. I combine data on household-level enrollment and plan-level claims from the Californian Affordable Care Act insurance...

We study age-rating restrictions in the health insurance marketplaces introduced by the Affordable Care Act. Because most buyers are subsidized, although age-rating restrictions affect pre-subsidy premiums, participation is primarily driven by subsidy generosity rather than pricing decisions....