并购是企业获取资源、提高竞争优势的重要途径之一。近年来，我国企业并购规模与数量持续攀升，越来越多的企业期望通过并购实现快速发展，提高企业绩效。但由于并购过程的复杂性与不确定性致使一些企业的并购绩效不升反降，因此研究影响并购绩效的因素成为学术界迫切关注的问题。当前，机构投资者在我国上市公司中的持股份额不断攀升，规模、信息以及专业优势使得机构投资者更倾向于积极主动地参与上市公司的经营管理。而并购作为企业重大的投资决策，必然会引起机构投资者的重点关注与积极参与，从而影响公司的并购绩效。为深入探究机构投资者异质性对企业并购绩效的影响，本文区分机构投资者为压力抵抗型和压力敏感型，以我国2009-2020年作为主并方发起并购的A股上市公司为研究样本，实证检验了机构投资者异质性对并购绩效的影响，以及管理层过度自信与管理层代理成本的中介作用。

主要研究结论如下：（1）机构投资者持股能够有效提升企业并购绩效，压力抵抗型机构投资者持股也促进了企业并购绩效的提升，压力敏感型机构投资者持股无法显著影响企业并购绩效。（2）压力抵抗型机构投资者能够抑制管理层过度自信进而提高并购绩效，即管理层过度自信在压力抵抗型机构投资者与并购绩效间发挥了中介作用。（3）压力抵抗型机构投资者能够降低管理层代理成本进而提高并购绩效，即管理层代理成本在压力抵抗型机构投资者与并购绩效间发挥了中介作用。（4）压力抵抗型机构投资者对并购绩效的积极作用会受到产权性质、股权制衡以及融资约束的影响，具体而言，在非国有企业、低股权制衡以及融资约束程度低的企业，压力抵抗型机构投资者的积极治理作用更明显。

本文研究丰富了机构投资者异质性对并购绩效影响的相关研究内容，拓宽了机构投资者异质性影响并购绩效内在机理的研究视角，也为企业合理引进外部机构投资者以提高并购绩效提供了经验证据。

Mergers and acquisitions (M&A) are one of the important ways for companies to acquire resources and improve their competitive advantage. In recent years, the scale and number of M&A activities by Chinese enterprises have continued to rise, and more and more companies expect to achieve rapid development and improve their performance through M&A. However, due to the complexity and uncertainty of the M&A process, the M&A performance of some companies has declined instead of improved, making it an urgent issue for the academic community to study the factors that affect M&A performance. Currently, institutional investors have been increasing their holdings in listed companies in China, and their size, information, and professional advantages make them more inclined to actively participate in the management of listed companies. As a major investment decision for companies, M&A will inevitably attract the attention and active participation of institutional investors, thereby affecting the M&A performance of companies. In order to explore in-depth the impact of institutional investor heterogeneity on M&A performance, this study distinguishes institutional investors as pressure-resistant and pressure-sensitive types. Using A-share listed companies that initiated M&A activities as the main subject from 2009 to 2020 in China as research samples, this study empirically examines the impact of institutional investor heterogeneity on M&A performance, as well as the mediating effects of management overconfidence and management agency costs.

The main research conclusions are as follows: (1) Institutional investor holdings can effectively improve the M&A performance of companies, and pressure-resistant institutional investor holdings also promote the improvement of M&A performance, while pressure-sensitive institutional investor holdings do not have a significant impact on M&A performance. (2) Pressure-resistant institutional investors can suppress management overconfidence and improve M&A performance, that is, management overconfidence plays a mediating role between pressure-resistant institutional investors and M&A performance. (3) Pressure-resistant institutional investors can reduce management agency costs and improve M&A performance, that is, management agency costs play a mediating role between pressure-resistant institutional investors and M&A performance. (4) The positive role of pressure-resistant institutional investors in M&A performance will be influenced by property rights, equity balance, and financing constraints. Specifically, in non-state-owned enterprises, companies with low equity balance and low financing constraints, the positive governance role of pressure-resistant institutional investors is more evident.

This study enriches the relevant research content on the impact of institutional investor heterogeneity on M&A performance, broadens the research perspective on the inherent mechanism of institutional investor heterogeneity's impact on M&A performance, and provides empirical evidence for companies to introduce external institutional investors to improve M&A performance.

Key words :  Heterogeneity of institutional investors; Management Overconfidence; Agency costs; M&A performance

Thesis    ： Application Research