The relentless conservative attack on the Affordable Care Act has been based on two deeply-held beliefs: That the individual mandate didn’t prompt people to buy health insurance, and that having coverage does nothing to make people healthier.

A new study conducted by a Stanford University researcher with the help of the Internal Revenue Service explodes both notions. It found that Americans who failed to respond to the individual mandate penalty when it was in effect (through 2018), tended to sign up for coverage when they were reminded about it; and that among those who did sign up, mortality rates fell.

