Can Vertical Mergers and Acquisitions of Renewable Energy Enterprises Enhance Supply Chain Resilience?—Empirical Verification Based on Multi-Period Difference-in-Differences Model

Given the global imperative for energy transition, vertical mergers and acquisitions (M&As) have become a strategic lever for renewable energy enterprises to enhance supply chain resilience. This study examines the performance of Chinese A-share listed renewable energy enterprises from 2011 to 2023. By constructing an evaluation index system for supply chain resilience, the study employs a multi-period difference-in-differences (DID) model to examine the impact of vertical M&As on supply chain resilience and the mediating effect of supplier concentration. The results demonstrate that the supply chain resilience of vertically merged renewable energy enterprises is generally stronger than that of non-M&A counterparts, with a significant upward trend observed in M&A enterprises during the study period. However, renewable energy enterprises demonstrate lower supply chain resilience compared to manufacturing firms. Vertical M&As in renewable energy enterprises enhance supply chain resilience, a conclusion that remains valid after a series of robustness tests. Vertical M&As mitigate supplier concentration and further enhance supply chain resilience in renewable energy enterprises. Heterogeneity analyses reveal that vertical M&A has a more pronounced effect on supply chain resilience in renewable energy enterprises that have low financing constraints and high growth potential. In the solar power, lithium and hydrogen energy industries, vertical M&As had a greater promoting effect on supply chain resilience. This study provides empirical evidence and decision-making guidelines for renewable energy enterprises to adopt vertical M&A strategies for enhancing supply chain resilience.