本研究針對 COVID-19 疫情情境下，具高自信特質的企業經理人是否會影響其投資行為與公司營運表現進行探討，並進一步評估公司治理機制是否能發揮調節作用。以 2018 至 2023 年台灣上市櫃非金融企業為對象，採用差異中之差法（Difference-in-Differences, DID）與普通最小平方法（Ordinary Least Squares, OLS）進行實證分析，並透過盈餘預測誤差衡量過度自信程度。實證結果指出，CEO 過度自信與資本支出呈正向關係，但此現象未在疫情期間達到統計顯著。此外，具高自信傾向之 CEO 所領導公司在財務表現（如 ROA）上呈現負面偏誤，顯示其高估企業績效可能導致資源錯置風險。進一步分析發現，若公司具備較高的治理強度，能有效緩解 CEO 投資決策偏差，凸顯良好治理機制的重要性與平衡功能。

This study explores how CEO overconfidence affects firms’ capital allocation and performance in the context of the COVID-19 pandemic, while also assessing whether corporate governance moderates this relationship. Using panel data from publicly listed non-financial firms in Taiwan between 2018 and 2023, the analysis applies Difference-in-Differences (DID) and Ordinary Least Squares (OLS) models to measure CEO overconfidence through revenue forecast bias and changes in ownership. The empirical findings reveal that CEOs exhibiting overconfidence tendencies tend to raise capital spending, though the effect does not become significantly stronger during the pandemic. Moreover, firms led by overconfident CEOs tend to exhibit lower return on assets (ROA), suggesting that such behavioral bias may lead to resource misallocation and operational inefficiencies. A triple-differences (DDD) analysis further reveals that strong corporate governance, particularly higher board ownership, can mitigate the excessive investment behaviors of overconfident CEOs. Overall, this study highlights the substantial influence of managerial traits under uncertain environments and affirms the role of governance as an effective internal control mechanism during crises.

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