Close elections are important for many reasons, including that consequent election disputes can weaken democratic legitimacy and risk political violence. We quantify the probability of close outcomes in U.S. presidential races with novel applications of empirical election models from several sources. We show that razor-thin margins are very likely under the Electoral College (EC). And we establish that the EC causes this closeness: It would not occur under any plausibly comparable popular vote system. The tendency of the EC to generate close elections is found today and throughout U.S. presidential voting history.

This paper examines the effects of privatizing social health insurance in the United States. We study this question in the context of the Medicaid program, the largest health insurer in the US and the largest means-tested program in the nation -serving over 90 million low-income families and individuals with disabilities. Exploiting a natural experiment wherein nearly 100,000 Medicaid enrollees were randomly assigned between a state-administered fee-for-service system and private managed care, we find that spending was nearly 10% lower for enrollees assigned to managed care plans. These savings were concentrated in prescription drugs, where we show that prior authorization was the key mechanism plans used to reduce overuse and encourage substitution to lower-cost alternatives without reducing quality. This was distinct from the effects of privatization on medical benefits, where private plans lowered quality and abraded consumers without achieving savings. In contrast to what our findings imply for an efficient public-private division of services, Medicaid has historically favored the public provision of prescription drugs and private outsourcing of medical care.