Every US state requires private health insurers to cover certain conditions, treatments, and providers. These benefit mandates were rare as recently as the 1960s, but the average state now has more than forty. These mandates are intended to promote the affordability of necessary health care....

Between 1992 and 2009, 29 US states adopted laws mandating that health insurance plans cover screenings for prostate cancer. Because prostate cancer screenings are used almost exclusively by men over 50, these mandates raise the cost of insuring older men relative to other groups. This paper...

Is there an obesity externality? A quasi-random natural experiment shows no evidence for the claim that the obese pass their health costs on to others through employer-based health insurance. In the late 1990’s and early 2000’s, many state governments began requiring health insurance plans...