Incentivizing efficient utilization without reducing access: The case against cost‐sharing in insurance
研究发现共担成本虽能减少道德风险，但会同时降低高效和低效医疗服务的利用，并因限制获取而产生两种新低效；而基于奖金的替代设计能实现相同激励且无副作用。
Cost-sharing is regarded as an important tool to reduce moral hazard in health insurance. Contrary to standard prediction, however, such requirements are found to decrease utilization both of efficient and of inefficient care. I employ a simple model that incorporates two possible explanations-consumer mistakes and limited access-to assess the welfare implications of different insurance designs. I find cost-sharing never to be an optimal solution as it produces two novel inefficiencies by limiting access. An alternative design, relying on bonuses, has no such side effects and achieves the same incentivization. I show how the optimal design can be deduced empirically and discuss possible impediments to its implementation.