绿色并购是促进企业实质性绿色转型还是沦为策略性回应的工具？为了解答这一问题，采用内容分析法手工收集重污染企业2007—2019年的绿色并购数据，运用多时点PSM—DID方法检验绿色并购对企业绿色技术创新的影响及内在作用机理。研究发现，绿色并购有效激励了企业绿色技术创新，经过平行趋势检验、安慰剂检验、熵平衡匹配等一系列稳健性检验后，该结论依然成立。机制分析发现，虽然绿色并购会消耗企业资源，但企业可以通过从内部挤出其它技术创新和从外部享受更多绿色创新补助两种途径为绿色技术创新提供资源支持。此外，绿色并购还具有改善媒体评价、提高企业社会责任绩效和提振投资者信心等溢出效应。上述证据表明，重污染企业绿色并购对绿色技术创新的激励效应并非是单一维度的，而是可以实现实质性绿色转型和绿色印象管理的“双赢”局面。拓展性分析发现，在政府环境规制力度强和媒体监督较为健全的地区，绿色并购对绿色技术创新的激励效应更显著。上述研究结论丰富了绿色并购与绿色技术创新的理论研究，同时，可为碳中和背景下重污染企业如何通过绿色并购实现实质性绿色转型提供决策参考。

Green technology innovation has become the new engine for high-quality economic development. For heavily polluting enterprises, there are two main paths to green technology innovation: internal environmental investment and green mergers and acquisitions (M&A). Herein, internal environmental investment refers to the enterprise's internal increase in green innovation investment, self-development of energy saving and emission reduction, clean production, and other areas of technology or energy to achieve green development. Green M&A is a type of M&A that incorporates green sustainable development into traditional technology M&A with the goal of energy conservation and environmental protection, as well as green and low-carbon development. In contrast to internal environmental investment, which has long cycles and uncertain outcomes, green M&A is faster and can quickly acquire the target enterprise in clean production. Simultaneously, as the Chinese government pays ongoing attention to environmental protection, more and more heavily polluting enterprises are keen on conducting green M&A.#br#However, the real intentions of heavily polluting enterprises' green M&A are vague. On the one hand, green M&A is essentially a major strategic reorganization behavior of enterprises, and it is a key approach to integrate various resources of the enterprises, modify the development mode, and promote social responsibility. On the other hand, the development of the Chinese capital market has not yet reached the stage of strong effectiveness, and severe information asymmetry still remains for investors, making flimsy M&A possible. As a consequence, the existing literature has not reached a consensus on whether green M&A is to achieve substantial green transformation or merely serve as a tool for strategic response.#br#To address this issue, this study compiles green M&A data from China's heavily polluting industries from 2007 to 2019.It constructs a staggered PSM-DID model to investigate the impact of green M&A on enterprises' green technology innovation and explore if green M&A can affect green technology innovation from the perspectives of internal and external resource support, adopting the green M&A event as a quasi-natural experiment. Furthermore, this study examines whether green M&A has other spillover effects in terms of media coverage, corporate social responsibility, and investor confidence. Taking into account the asymmetry impact of the external environment on the green innovation incentive effect of green M&A, this study also confirms the cross-sectional impact difference of green M&A on enterprise green technology innovation from the perspectives of environmental regulations and media supervision.#br#It is concluded that firstly, green M&A enterprises possess much higher levels of green technology innovation than non-green M&A enterprises. Following a series of robustness tests, it discovers that green M&A greatly boosts green technology innovation and appears to be sustainable. Second, despite consuming large amounts of resources, green M&A can motivate enterprise green technology innovation primarily by squeezing out other technological innovations (internal resource support) and enjoying increased government green innovation subsidies (external resource support). Thirdly, green M&A also has other spillover effects, which can improve media coverage, enhance social responsibility performance, and boost investor confidence, showing the role of impression management. In addition, stricter environmental regulations and more media coverage can reinforce the relationship between green M&A and green innovation. #br#Different from the existing studies, the marginal contributions are reflected in the following aspects.First, this study examines the objective manifestations of green M&A affecting enterprise green technology innovation, enriching the literature of the influence factors of green technology innovation and simultaneously providing micro-level evidence for the debate on the “synergy” or “constraint” between green M&A and green technology innovation. Second, by employing the staggered PSM-DID method to reveal the relationship between green M&A and green technology innovation, this study effectively controls the potential endogeneity problems, avoiding the limitations of the existing studies that directly adopt dummy variables as a substitute for green M&A for ordinary regression analysis, thereby improving the accuracy of the conclusions. Third, from the “competition perspective” of green technology innovation and other technology innovation, and the “impression management perspective” of green innovation subsidies, along with the heterogeneity analysis of environmental regulations and media supervision, this study reveals the mechanism of green M&A in influencing enterprise green technology innovation. Overall, this study provides scientific evidence for the role of green M&A in stimulating green innovation in the context of carbon neutrality for heavily polluting enterprises.#br#