The Price Ain’t Right? Hospital Prices and Health Spending on the Privately Insured*
Quarterly Journal of Economics · 2018 · Zack Cooper、Stuart Craig、Martin Gaynor、John Van Reenen
中文摘要
我们使用覆盖美国雇主提供的医疗保险参保人总数28%的保险理赔数据，研究私人医疗保险参保人的医疗支出差异，考察保险公司与医院之间的合同结构，并分析全国范围内医院价格的差异。不同地理区域的私人医疗保险参保人人均医疗支出存在三比一的差距，且与美国联邦医疗保险（Medicare）支出的相关性极低。对于私人医疗保险参保人，支出差异的一半由地区间的价格差异驱动，另一半由医疗服务数量差异驱动。价格在不同地区之间、同一地区的不同医院之间，甚至同一医院内部，都存在很大差异。例如，即便是下肢磁共振成像这类近乎同质的服务，在横截面上，病例层面价格总变异的约五分之一也来自同一医院内部。医院市场结构与价格水平及合同结构密切相关。垄断医院的价格比处于有四个或更多竞争对手的市场中的医院高12%。垄断医院的合同还让保险公司承担更多风险（例如，更多病例的价格按医院标价的一定比例确定）。在集中度较高的保险公司市场中，情况则相反：医院价格较低，且承担更多财务风险。通过考察2007年至2011年间发生的366起并购，我们发现，当参与合并的医院地理位置相近时（例如，相距不超过5英里），价格上涨超过6%；但当医院地理位置相距较远时（例如，相距超过25英里），价格并未上涨。
Abstract
We use insurance claims data covering 28% of individuals with employer-sponsored health insurance in the United States to study the variation in health spending on the privately insured, examine the structure of insurer-hospital contracts, and analyze the variation in hospital prices across the nation. Health spending per privately insured beneficiary differs by a factor of three across geographic areas and has a very low correlation with Medicare spending. For the privately insured, half of the spending variation is driven by price variation across regions, and half is driven by quantity variation. Prices vary substantially across regions, across hospitals within regions, and even within hospitals. For example, even for a nearly homogeneous service such as lower-limb magnetic resonance imaging, about a fifth of the total case-level price variation occurs within a hospital in the cross section. Hospital market structure is strongly associated with price levels and contract structure. Prices at monopoly hospitals are 12% higher than those in markets with four or more rivals. Monopoly hospitals also have contracts that load more risk on insurers (e.g., they have more cases with prices set as a share of their charges). In concentrated insurer markets the opposite occurs-hospitals have lower prices and bear more financial risk. Examining the 366 mergers and acquisitions that occurred between 2007 and 2011, we find that prices increased by over 6% when the merging hospitals were geographically close (e.g., 5 miles or less apart), but not when the hospitals were geographically distant (e.g., over 25 miles apart).