This research employs a difference-in-differences framework to study the impact of major board reforms on the performance of mergers and acquisitions (M&As). Using an international sample of board reforms implemented in 61 countries from 1985 to 2021, we document a drastic redistribution of wealth from target shareholders to acquirer shareholders after the board reforms in target countries. This effect is most pronounced in M&A transactions that involve the sale of controlling shares, thereby supporting the hypothesis that corporate board reforms mitigate the private benefits of control in the target firm. Furthermore, these reforms increase expected deal synergies, in that deal-level announcement returns are higher after the implementation of the reforms. When country-level institutional quality and legal protection of shareholders are greater, it reinforces the reform effects. Overall M&A activity remains unchanged following the reforms, yet financial bidders complete fewer transactions, implying a reform-induced squeeze-out of financial bidders from the M&A market in the target country. Collectively, these international results are consistent with the predictions of the private benefits of control theory and underscore the role of institutional quality and investor protection in reinforcing the effects of board reforms worldwide.

本研究采用双重差分框架来研究主板改革对并购绩效的影响。我们利用 1985 年至 2021 年 61 个国家实施的董事会改革的国际样本，记录了目标国家董事会改革后，财富从目标股东到收购方股东的剧烈重新分配。这种效应在涉及出售控股权的并购交易中最为明显，从而支持了公司董事会改革减轻了目标公司控制权的私人利益的假设。此外，这些改革增加了预期的交易协同效应，因为改革实施后交易层面的公告回报率更高。当国家层面的制度质量和对股东的法律保护更强时，改革效果就会增强。改革后，总体并购活动保持不变，但金融投标人完成的交易减少，这意味着改革导致金融投标人被挤出目标国的并购市场。总的来说，这些国际结果与控制理论的私人利益预测一致，并强调了制度质量和投资者保护在加强全球董事会改革效果方面的作用。