近年來，共同機構持股（Common Institutional Ownership， CIO）對企業決策、公司治理與產品市場競爭之影響，已成為公司財務與產業組織文獻的重要議題。相較於一般企業社會責任議題，工作場所安全（Workplace Safety）更直接涉及員工福祉、法規遵循、事故成本與企業長期價值，因此共同機構持股是否能改善企業職場安全，仍為值得檢驗之實證問題。本文旨在探討共同機構持股與企業工作場所安全之關聯，並進一步檢驗其可能機制與條件效果。 本文以2002年至2011年美國上市公司為研究樣本，結合Compustat財務資料、LSEG Thomson Reuters 13F 機構持股資料，以及OSHA工作場所安全資料，建構公司－年度（Firm-Year）層級樣本。本文以員工標準化後之職災發生率作為主要職場安全衡量，衡量一年內受傷員工人數占公司總員工人數之比例，並以多項共同機構持股指標捕捉共同持股之廣度、連結程度與持股強度。實證模型控制公司特徵變數，並納入年度固定效果與產業固定效果，以公司層級進行聚類標準誤調整。 實證結果顯示，共同機構持股與工作場所安全之間存在顯著負向關係，亦即共同機構持股程度愈高，企業受職災影響之員工比例較低，表示其工作場所安全表現較佳。此結果在更換不同職災衡量指標與不同共同機構持股代理變數後仍然穩健。進一步地，本文透過傾向分數配對法（Propensity Score Matching， PSM）控制樣本可比性問題後，主要結論仍然成立；而以金融機構併購作為共同機構持股外生衝擊所建構之雙重差分法（Difference-In-Differences， DID）分析，亦顯示共同機構持股上升後，企業嚴重工傷相關指標顯著下降，支持共同機構持股對改善工作場所安全具有較強之識別力。此外，機制分析結果指出，共同機構持股對職場安全之正向效果，主要出現在競爭較激烈之產業中；當產業集中度較高時，此一效果則明顯減弱。異質性分析進一步顯示，共同機構持股對降低職災風險之效果，在低工會涵蓋企業中更為顯著。整體而言，本文結果較支持共同機構持股透過治理與監督機制改善企業工作場所安全，而非單純透過反競爭效果削弱員工福祉。 本文之貢獻在於，將共同機構持股文獻由一般企業社會責任延伸至職場安全此一更具體且具有直接經濟後果之面向，並補充所有權結構如何影響員工安全與企業非財務結果之相關研究。本文亦指出，共同機構持股之經濟效果具有結果變數特定性，不能直接將其對一般企業社會責任之影響，推論至所有員工福祉或利害關係人面向。;This study examines the association between common institutional ownership (CIO) and workplace safety. While prior studies suggest that CIO may affect firms’ governance， competition， and non-financial outcomes， its impact on workplace safety remains unclear. Because workplace safety is directly related to employee welfare， regulatory compliance， accident costs， and firms’ long-term value， it provides an important setting for evaluating the economic consequences of CIO. Using a sample of U.S. listed firms from 2002 to 2011， this study combines Compustat financial data， LSEG Thomson Reuters 13F institutional ownership data， and OSHA workplace safety data to construct a firm-year dataset. Workplace safety is measured by workplace injuries normalized by the number of employees， and CIO is captured by multiple measures reflecting the breadth， connectedness， and intensity of common ownership. The empirical models include firm-level controls， year fixed effects， and industry fixed effects， with standard errors clustered at the firm level. The results show that CIO is significantly negatively associated with employee injury rates， suggesting that firms with higher levels of common institutional ownership have better workplace safety outcomes. This finding remains robust across alternative measures of workplace safety and common ownership. In addition， the results continue to hold after propensity score matching， and a difference-in-differences design based on financial institution mergers provides further support for a causal interpretation. Further analyses show that the beneficial effect of CIO on workplace safety is stronger in more competitive industries， and in firms with lower union coverage. Overall， the evidence suggests that CIO is more closely associated with governance and monitoring benefits than with anti-competitive effects in the context of workplace safety.
