Unintended consequences of health insurance: Affordable Care Act's free contraception mandate and risky sex
利用平价医疗法案中避孕药具零自付强制令，研究发现该政策降低了生育率，但导致安全套使用减少和性传播感染增加，揭示了保险对风险行为的非预期影响。
Health insurance is a primary driver of rising medical expenditures. Economic theory suggests that insurance induces an increase in risky behaviors, but previous empirical evidence is mixed. I use a mandate in the Affordable Care Act in which contraceptives were covered at zero cost to consumers to test for unintended effects of insurance on risky sex. Leveraging mandated zero cost-sharing for contraception and pre-policy insured rates as a measure of treatment intensity, I provide evidence that this 2012 policy reduced fertility but caused unintended consequences: a decline in condom use and a subsequent increase in sexually transmitted infections (STIs). I discuss shortcomings of controlling for nonparallel pre-trends using state-trends, and I suggest an alternative to control for pre-trends directly in the context of dose-response difference-in-differences. Finally, estimates based on the 2010 dependent coverage mandate indicate health insurance provides an overall net positive effect on insurance and STI prevention.