Standardization of complex products is touted as improving consumer decisions and intensifying price competition, but evidence on standardization is limited. We examine a natural experiment: the standardization of health insurance plans on the Massachusetts Health Insurance Exchange....

I use the Medicare Part D prescription drug insurance market to examine the dynamics of firm interaction with consumers on an insurance exchange. Enrollment data show that consumers face switching frictions leading to inertia in plan choice, and a regression discontinuity design indicates...