Public health insurance and disparate eligibility of spouses: The Medicare eligibility gap.

I exploit the age-based eligibility structure of Medicare and the age gap between spouses to examine the impact of Medicare eligibility of an older spouse on the insurance coverage of younger, Medicare-ineligible spouses. Using a regression discontinuity framework, I find that Medicare eligibility of an older spouse can crowd-out the health insurance coverage of a younger spouse. Medicare eligibility of older wives increases the likelihood that younger husbands are uninsured. Younger wives are less likely to be covered through an employer-based plan and more likely to have non-group coverage after an older husband turns 65.