解構獨立董事任期與產業經驗對公司財務績效之影響

Abstract

本研究旨在探討獨立董事的任期與產業經驗對公司財務績效的影響，並解構兩者各自扮演的角色及其交互作用。本研究使用1990年至2025年共14,471家美國上市公司為樣本，進行實證分析。 研究首先重現了既有文獻的發現，驗證了獨立董事任期與公司財務績效之間存在倒 U 型非線性關係，並以此為基礎，延伸探討獨董產業經驗的影響，特別聚焦於其在加入現任董事會前的過往產業經驗。實證結果顯示，考慮獨董任期後，過往產業經驗與公司績效則呈現出正U型的非線性關係，亦即初期產業經驗可能對公司財務績效產生負面影響，但隨著經驗累積，此負面效果逐漸遞減並轉為正向。進一步分析發現，過往產業經驗並未顯著強化或替代任期對公司績效的正向作用，顯示僅具豐富過往產業背景尚不足以取代長期任職所帶來的績效貢獻。 此外，研究也發現公司規模對此關係存在調節作用，獨董任期的倒U型影響在小型公司中最為顯著，而過往產業經驗的負面影響在中大型公司中更為顯著。現金部位較高的公司更容易受到過往產業經驗的負面影響。 總結而言，本研究釐清了獨立董事任期與產業經驗在影響公司財務績效上的不同機制，並揭示兩者無顯著的互補效果。研究建議公司在選任獨立董事時應同時權衡其任期長度與產業背景，以實現最佳的公司治理成效。研究貢獻在於深入剖析過往產業經驗與任期對公司績效的非線性影響，進一步釐清兩者的互動關係，並揭示公司規模與現金部位所發揮的調節作用。

This study investigates the respective and interaction effects of tenure and industry experience of independent directors (IDs) on corporate financial performance. Using a dataset comprising 14,471 U.S. listed companies from 1990 to 2025, I conduct an empirical analysis to explore these relationships. I first replicate findings from prior studies and confirm the existence of an inverted U-shaped nonlinear relationship between IDs’ tenure and firm performance. Then I examine the effect of IDs’ industry experience by focusing on prior industry experience—that is, experience before joining the current boards. My results suggest that prior industry experience exhibits a U-shaped relationship with firm performance, indicating a potential negative impact early on that gradually diminishes and turns positive as experience accumulates. However, further analysis reveals that prior industry experience does not significantly mitigate the positive effect of tenure on firm performance. This implies that prior experience alone cannot fully replace the benefits of long-term board service. Additionally, firm characteristics moderate these relationships. The effect of tenure is most pronounced in smaller firms, whereas that of prior industry experience is more evident in medium to large firms. Companies with higher cash holdings are affected more negatively by prior industry experience. In sum, this study clarifies the distinct mechanisms through which IDs’ tenure and industry experience affect firm performance and finds no significant complementary effect between the two. The findings suggest that firms should consider both tenure and prior industry background when appointing IDs to optimize governance outcomes. This study contributes to the literature by offering a nuanced understanding of the nonlinear impacts of tenure and industry experience, their interaction effects, and the moderating roles of firm size and cash holdings.