能源企业绿色并购何时最优？——基于最优停时模型的时机选择研究

When Is the Optimal Timing for Green Merger and Acquisition in Energy Enterprises? —A Research Based on an Optimal Stopping Model

摘要: 绿色并购是能源企业实现低碳转型的重要途径，但其决策过程面临技术迭代、政策变动与市场波动等多重随机性挑战。本文引入最优停时理论，构建能源企业绿色并购时机的实物期权决策模型，将标的资产价值刻画为几何布朗运动，并购协同收益设为时变线性函数，通过求解自由边界问题确定最优并购边界。以大唐集团收购西藏清洁能源资产为案例进行实证分析，结果表明：在当前参数设定下，最优并购时机约为2027年中期，等待具有显著的期权价值。研究为企业绿色并购决策提供了量化工具，并为政府完善碳市场机制、降低政策不确定性提供了参考依据。

Abstract: Green mergers and acquisitions (M&As) serve as a crucial pathway for energy enterprises to achieve low-carbon transition. However, the decision-making process faces multiple stochastic challenges, including technological iteration, policy changes, and market fluctuations. This paper introduces optimal stopping theory to construct a real options decision model for the timing of green M&As by energy enterprises. The underlying asset value is characterized as a geometric Brownian motion, while the synergistic benefits of M&A are modeled as a time-varying linear function. The optimal M&A boundary is determined by solving a free-boundary problem. Taking China Datang Corporation’s acquisition of clean energy assets in Xizang as a case study, the empirical results indicate that, under the current parameter settings, the optimal timing for the M&A is around mid-2027, with waiting exhibiting significant option value. This research provides a quantitative tool for enterprises’ green M&A decision-making and offers reference for the government to improve the carbon market mechanism and reduce policy uncertainty.