Regulating Markups in US Health Insurance
研究了《平价医疗法案》中最低医疗损失率规定如何激励保险公司增加医疗支出，而非降低保费，对政策制定者和健康保险市场参与者有参考价值。
A health insurer's Medical Loss Ratio (MLR) is the share of premiums spent on medical claims, or the inverse markup over average claims cost. The Affordable Care Act introduced minimum MLR provisions for all health insurance sold in fully insured commercial markets, thereby capping insurer profit margins, but not levels. While intended to reduce premiums, we show this rule creates incentives to increase costs. Using variation created by the rule's introduction as a natural experiment, we find medical claims rose nearly one-for-one with distance below the regulatory threshold: 7 percent in the individual market and 2 percent in the group market. Premiums were unaffected.