Disadvantaging Rivals: Vertical Integration in the Pharmaceutical Market
研究了制药市场中药房福利管理公司与保险公司之间的纵向整合，发现2015年一次大型合并导致竞争对手保费上涨，但未给消费者带来保费降低的好处。
The pharmaceutical market has experienced a wave of vertical integration between pharmacy benefit managers (PBMs) and insurers in recent years. Using a unique dataset on insurer-PBM contracts, we document increasing vertical integration in Medicare Part D. Next, we evaluate the effects of a large insurer-PBM merger in 2015, assessing the trade-offs of vertical integration—harms to competition on the one hand and improved efficiency on the other. We find premium increases for rival insurers post-merger, consistent with vertically integrated PBMs raising costs through input foreclosure. We find no evidence of benefits to consumers of the merged firm from lower premiums.