This paper studies bank antitrust rules which discontinuously shift bank mergers' competitive impact. The likelihood of mandatory divestiture rises sharply for mergers in markets above a threshold level of concentration, leading to an increase in the number of banks in these markets. Consistent with greater competition, intervention leads to higher deposit rates. Mortgage originations rise by 11%, from both refinancing and purchases. However, small business loan quantities do not change. The effects of intervention do not dissipate over time, and nonbank lenders respond similarly to banks. Overall, antitrust rules can increase bank competition, but relationships protect banks from competitors.

中文翻译：

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竞争如何影响零售银行业务？银行合并的准实验证据

本文研究了不连续地改变银行合并竞争影响的银行反垄断规则。对于集中度超过阈值的市场中的合并，强制剥离的可能性急剧上升，导致这些市场中银行数量的增加。与更激烈的竞争相一致，干预会导致存款利率上升。再融资和购买的抵押贷款发放量增长了 11%。然而，小企业贷款数量没有变化。干预的影响不会随着时间的推移而消失，非银行贷款机构的反应与银行类似。总体而言，反垄断规则可以增加银行竞争，但关系可以保护银行免受竞争对手的侵害。