Cost sharing and the demand for health services in a regulated market
利用哥伦比亚医疗市场的断点回归设计，发现更高的共保率会减少患者对医疗服务的需求，包括预防性服务，且不会转向更贵的供应商。
This paper measures consumer responsiveness to cost sharing in healthcare using a regression discontinuity design. I use a novel and detailed claims-level dataset from the Colombian healthcare market, where the government exogenously determines a tier system for coinsurance rates and copays based on the enrollee's monthly income. I find that patients exposed to higher coinsurance rates demand fewer services relative to patients facing lower cost sharing. This reduction holds for both discretionary and preventive services. Lower utilization translates into lower costs, despite evidence that patients facing higher prices do not substitute away from more expensive providers.