企業ESG表現與公司避稅傾向關聯性之研究──以美國併購事件為例

A Study of the Association between ESG Performance and Tax Avoidance—Evidence from Mergers and Acquisitions in the United States

本研究以2010-2021年美國上市公司併購事件為樣本，探討收購方併購前的ESG表現與併購後避稅傾向之關係，並檢驗股權結構的調節效果。實證結果支持股東價值極大化觀點：收購方在併購前一年的整體ESG、環境與社會構面表現，皆與併購後的有效稅率呈顯著負相關，顯示企業可能藉由提升ESG績效（尤其在能見度較高的環境與社會構面）作為「聲譽保險」或「道德資本」，以緩解積極租稅規劃的外部壓力。即使控制內生性後，負向關係仍顯著。內部人股權集中度與機構法人持股對此關係無顯著調節效果。進一步以Huseynov and Klamm（2012）的S&P 500成分股重新檢驗後，結果顯示2010-2021年間，大型公司ESG表現愈佳者愈積極承擔稅負責任，與2000-2008年無顯著關聯的結果不同。相對地，非S&P 500公司與併購樣本一致，仍展現以ESG績效掩飾避稅的特徵。

Using U.S. merger data from 2010 to 2021, this study examines the relationship between acquirers’pre-merger ESG performance and their post-merger tax avoidance, as well as whether ownership structure characteristics moderate this relationship. The empirical findings support the shareholder value maximization view. Acquirers’overall ESG, environmental, and social scores in the year prior to acquisition are significantly negatively associated with post-merger effective tax rates, suggesting that firms may use strong ESG performance—particularly in more visible environmental and social dimensions—as a form of“reputation insurance”or“moral capital”to mitigate stakeholder scrutiny arising from aggressive tax planning. The negative ESG–tax relationship remains robust after controlling for endogeneity. Insider ownership concentration and institutional ownership show no significant moderating effects. Re-examining S&P 500 firms following Huseynov and Klamm (2012), this study finds that, unlike the 2000–2008 period, where no significant link was observed, ESG-strong large firms between 2010 and 2021 display greater tax responsibility consistent with corporate citizenship behavior. In contrast, non-S&P 500 firms exhibit results similar to the acquisition sample, using ESG performance to mask tax avoidance aimed at maximizing shareholder value.