Northwestern University, Kellogg School of Management, Evanston, IL.
Am Econ Rev. 2010 Sep;100(4):1399-431. doi: 10.1257/aer.100.4.1399.
To gauge the competitiveness of the group health insurance industry, I investigate whether health insurers charge higher premiums, ceteris paribus, to more profitable firms. Such "direct price discrimination" is feasible only in imperfectly competitive settings. Using a proprietary national database of health plans offered by a sample of large, multisite firms from 1998–2005, I find firms with positive profit shocks subsequently face higher premium growth, even for the same health plans. Moreover, within a given firm, those sites located in concentrated insurance markets experience the greatest premium increases. The findings suggest health care insurers are exercising market power in an increasing number of geographic markets.
为了评估团体健康保险行业的竞争力，我调查了健康保险公司是否会在其他条件相同的情况下向更盈利的公司收取更高的保费。这种“直接价格歧视”只有在不完全竞争的情况下才可行。利用 1998 年至 2005 年期间来自大型多地点公司样本的全国性健康计划专有数据库，我发现利润出现正冲击的公司随后会面临更高的保费增长，即使是针对相同的健康计划。此外，在给定的公司内，那些位于保险市场集中的地点的公司会经历最大的保费增长。这些发现表明，医疗保险公司在越来越多的地理市场中行使市场力量。
