Richard M. Scheffler (
Daniel R. Arnold is a postdoctoral fellow in health economics at the Nicholas C. Petris Center on Health Care Markets and Consumer Welfare, University of California, Berkeley.
Health Aff (Millwood). 2017 Sep 1;36(9):1539-1546. doi: 10.1377/hlthaff.2017.0552.
Using prices of hospital admissions and visits to five types of physicians, we analyzed how provider and insurer market concentration-as measured by the Herfindahl-Hirschman Index (HHI)-interact and are correlated with prices. We found evidence that in the range of the Department of Justice's and Federal Trade Commission's definition of a moderately concentrated market (HHI of 1,500-2,500), insurers have the bargaining power to reduce provider prices in highly concentrated provider markets. In particular, hospital admission prices were 5 percent lower and cardiologist, radiologist, and hematologist/oncologist visit prices were 4 percent, 7 percent, and 19 percent lower, respectively, in markets with high provider concentration and insurer HHI above 2,000, compared to such markets with insurer HHI below 2,000. We did not find evidence that high insurer concentration reduced visit prices for primary care physicians or orthopedists, however. The policy dilemma that arises from our findings is that there are no insurer market mechanisms that will pass a portion of these price reductions on to consumers in the form of lower premiums. Large purchasers of health insurance such as state and federal governments, as well as the use of regulatory approaches, could provide a solution.
利用住院和五种类型医生就诊的价格，我们分析了供应商和保险公司市场集中程度（用赫芬达尔-赫希曼指数（HHI）衡量）如何相互作用并与价格相关。我们有证据表明，在司法部和联邦贸易委员会定义的中度集中市场（HHI 为 1500-2500）范围内，保险公司具有讨价还价的能力，可以降低高度集中的供应商市场中的供应商价格。特别是，在供应商高度集中且保险公司 HHI 高于 2000 的市场中，与保险公司 HHI 低于 2000 的市场相比，医院入院价格分别降低了 5%，心脏病专家、放射科医生和血液科/肿瘤科就诊价格分别降低了 4%、7%和 19%。然而，我们没有发现证据表明高保险公司集中程度降低了初级保健医生或矫形外科医生的就诊价格。我们的研究结果带来的政策困境是，没有保险公司市场机制可以将这些价格降低的一部分以较低的保费形式转嫁给消费者。州和联邦政府等医疗保险的大型购买者，以及监管方法的使用，可能是一个解决方案。
