Question: The mandatory coverage provision of the ACA: Presently, US citizens must report on their tax return whether they have health insurance coverage, and if they are not covered by an employer and also opt out of the insurance exchange they are charged a fine. The bill introduced to and withdrawn from the 115th Congress made insurance coverage voluntary. This creates a problem of adverse selection and would undoubtedly raise premiums for employers and those who are privately insured. Can you think of ways that we might address the disparity in risk between young people and older people, those with preconditions and those without, groups that are higher risk because of environmental conditions? Would it be possible (and acceptable) to have highly resolute categories of risk that are charged different premiums so that risk-sharing is not absolute? For example, older people would pay higher premiums than younger people but not as high as they would if there were no young people at all in the pool. Private insurance does presently use resolute risk categories, but group insurance does not. Are there ways to make legally-required insurance more attractive and acceptable to low-risk people by making it resemble more the private insurance markets?