Scheffler Richard M, Arnold Daniel R, Fulton Brent D, Glied Sherry A
Richard M. Scheffler (
Daniel R. Arnold is a graduate student researcher at the University of California, Berkeley, and a doctoral student in economics at the University of California, Santa Barbara.
Health Aff (Millwood). 2016 May 1;35(5):880-8. doi: 10.1377/hlthaff.2015.1229.
Recent increases in market concentration among health plans, hospitals, and medical groups raise questions about what impact such mergers are having on costs to consumers. We examined the impact of market concentration on the growth of health insurance premiums between 2014 and 2015 in two Affordable Care Act state-based Marketplaces: Covered California and NY State of Health. We measured health plan, hospital, and medical group market concentration using the well-known Herfindahl-Hirschman Index (HHI) and used a multivariate regression model to relate these measures to premium growth. Both states exhibited a positive association between hospital concentration and premium growth and a positive (but not statistically significant) association between medical group concentration and premium growth. Our results for health plan concentration differed between the two states: It was positively associated with premium growth in New York but negatively associated with premium growth in California. The health plan concentration finding in Covered California may be the result of its selectively contracting with health plans.
近期，健康保险计划公司、医院和医疗集团的市场集中度不断提高，这引发了人们对这类合并对消费者成本有何影响的质疑。我们研究了2014年至2015年期间，市场集中度对《平价医疗法案》两个基于州的市场中医疗保险保费增长的影响：加州医保（Covered California）和纽约州健康保险市场（NY State of Health）。我们使用著名的赫芬达尔-赫希曼指数（HHI）来衡量健康保险计划公司、医院和医疗集团的市场集中度，并使用多元回归模型将这些指标与保费增长联系起来。两个州均显示，医院集中度与保费增长之间呈正相关，医疗集团集中度与保费增长之间呈正相关（但无统计学意义）。我们关于健康保险计划公司集中度的研究结果在两个州有所不同：在纽约，它与保费增长呈正相关，而在加州，它与保费增长呈负相关。加州医保市场中健康保险计划公司集中度的这一结果，可能是其与健康保险计划公司选择性签约的结果。
