Great article by Emily Oster and Geoffrey Kocks on vaccination in California:

Under-vaccination is a significant policy problem. As earlier generations knew, people die of measles, and of whooping cough, and of other diseases that vaccines can prevent. Figuring out how to increase vaccination is a challenge. We often rely on education, but it is hard to change people’s minds on this topic, as doctors and policymakers — as well as any parents who have engaged on an internet message board — know all too well.

From a policy standpoint, these findings offer a ray of hope for vaccine proponents. Maybe changing minds isn’t so important. People may not have altered their attitudes about vaccination, but the fact is that these laws actually changed behavior.

In Oregon, parents can opt out of getting their children immunized by completing a 15-minute online “education” module. Many of them do: The share of people in Oregon counties with kindergarten vaccination rates over 95 percent was close to 100 percent in 2000; in 2015, it was about 30 percent. Perhaps lawmakers there and in other states should consider a more stringent exemption policy before, not after, they have their own measles outbreak.