股權結構、董事會特性與公司績效之關係，為當代組織策略學者廣泛討論之議題。現有文獻中，股權集中度與董事年資對於公司績效到底有正向或負向的影響，卻有不一致的研究結果。本研究實證探討股權結構（包括大股東股權集中度、外部法人持股）與外部董事年資對公司績效之影響，採用2011至2013年台灣708家上市公司的三年期資料。研究結果發現，大股東股權集中度與公司績效之間並非現有文獻主張的單純線性關係，而是先升後降的倒U型曲線關係；同樣地，外部法人持股比例與外部董事年資，對於公司績效同樣存在先升後降的倒U型曲線關係。本研究的結果對於過往學術研究的不一致結論，提供了可能的學術解釋。

The relationship between ownership structure, board composition and firm performance has been an increasingly important topic in organization and strategy research. Regarding whether shareholding concentration and director tenure have a positive or negative impact on firm performance, existing literature however reports inconsistent findings. This study empirically examines how shareholding structure (specifically, large shareholding and institutional shareholding) and outside director tenure influence firm performance, by using data collected from 708 Taiwanese public firms during the period of 2011-2013. The results show that large shareholding, institutional shareholding and outside director tenure influence firm performance in a nonlinear manner. Their influences are positive in the beginning and turn into negative when going beyond a certain degree, suggesting an inverted U-shaped relationship. Findings of this study are expected to shed new lights on the inconsistent findings of prior academic studies.

根據OECD公司治理原則，企業能真正保障股東權益者，可謂具有創業家精神。近年美國的恩隆案、台灣的力霸掏空案等，傷害的是所有利害關係人之權益，更讓落實股東權益保障的議題更顯重要。 過去半世紀以來學者根據代理理論探討公司治理機制，現有學術文獻指出，當經理人追求的利益與股東不相同時，會導致傳統的型一代理問題，故建議增加股東力量以有效監督經理人做出有利股東之決策；但當大股東股權集中度過高時，大股東也可能豪奪小股東之利益，造成大小股東之間的代理問題，亦即型二代理問題。換言之，為了避免型一代理問題，公司致力於擴大股東力量，反倒可能衍生出型二代理問題。此外，增加外部股東的監視力量，也是解決代理問題的可能方式之一，但若持續擴大外部股東股權又可能稀釋大股東權益，失去與經理人相抗衡之優勢，如此又回到型一代理問題。此時，若能引進外部董事以強化董事會的監督功能，也可能降低型一與型二代理問題。因此，如何設計平衡的股權結構並健全董事會之機制，實為提升公司經營績效的重要議題。 本研究以台灣上市公司為研究對象，提出企業應同時考慮大股東股權集中度、外部法人持股、外部董事年資等公司治理機制。本研究發現這三種公司治理機制對於公司績效均呈現顯著的倒U型效果，意味著這些公司治理機制對公司績效存在某個最適的決策點。公司高層必須注意大股東與外部股東持股比例的結構變化，方能真正透過股權結構來激勵其發揮監督治理之功能，以避免力量過小或過大時對公司績效之不良影響。公司也必須注意外部董事的任期年資，異動頻繁可能隱含該公司功能不健全，而萬年董事又可能喪失監督功能，因此公司應適時調整以確保董事會的監督品質，以提升經營績效。這和金管會於2017年研擬修法，獨立董事任期若超過三屆則必須揭露的規範相當一致。本研究的發現和當代公司治理實務互相呼應，提供學術界、企業界、政府相關單位具體的參考依據。

Agrawal, A. and Mandelker, G. N., 1990, “Large Shareholders and the Monitoring of Managers: The Case of Antitakeover Charter Amendments,” Journals of Financial and Quantitative Analysis, Vol. 25, No. 2, 143-161.
Ayadi, F., Dufrene, U. B., and Obi, C. P., 1996, “Firm Performance Measures: Temporal Roadblock to Innovation?” Managerial Finance, Vol. 22, No. 8, 18-32.
Barclay, M. J. and Holderness, C. G., 1991, “Negotiated Block Trades and Corporate Control,” Journal of Finance, Vol. 46, No. 3, 861-878.
Basu, N., Paeglis, I., and Rahnamaei, M., 2016, “Multiple Blockholders, Power, and Firm Value,” Journal of Banking and Finance, Vol. 66, 66-78.
Beiner, S., Drobetz, W., Schmid, M. M., and Zimmermann, H., 2006, “An Integrated Framework of Corporate Governance and Firm Valuation,” European Financial Management, Vol. 12, No. 2, 249-283.
Berle, A. A. and Means, C. G., 1932, The Modern Corporation and Private Property, 2nd, New York: Commerce Clearing House.
Boeker, W., 1997, “Executive Migration and Strategic Change: The Effect of Top Manager Movement on Product-market Entry,” Administrative Science Quarterly, Vol. 42, No. 2, 92-124.
Brickley, J. A., Lease, R. C., and Smith, C. W., 1988, “Ownership Structure and Voting on Antitakeover Amendments,” Journal of Financial Economics, Vol. 20, No. 1, 267-291.
Burt, R. S., 2004, “Structural Holes and Good Ideas,” American Journal of Sociology, Vol. 110, No. 2, 349-399.
Claessens, S., Djankov, S., and Larry, L. H. P., 2000, “The Separation of Ownership and Control in East Asian Corporations,” Journal of Financial Economics, Vol. 58, No. 1-2, 81-112.
Chen, T., 2015, “Institutions, Board Structure, and Corporate Performance: Evidence from Chinese Firms,” Journal of Corporate Finance, Vol. 32, 217-237.
Choi, J. J., Park, S. W., and Yoo, S. S., 2007, “The Value of Outside Directors: Evidence from Corporate Governance Reform in Korea,” Journal of Financial and Quantitative Analysis, Vol. 42, No. 4, 941-962.
Connelly, J. T., Limpaphayom, P., and Nagarajan, N. J., 2012, “Form versus Substance: The Effect of Ownership Structure and Corporate Governance on Firm Value in Thailand,” Journal of Banking & Finance, Vol. 36, No. 6, 1722-1743.
Dechow, P. M., Sloan, R. G., and Sweeney, A. P., 1996, “Causes and Consequences of Earnings Manipulation: An Analysis of Firms Subject to Enforcement Actions by the SEC,” Contemporary Accounting Research, Vol. 13, No. 1, 1-36.
Demsetz, H., 1983, “The Structure of Ownership and the Theory of the Firm,” Journal of Law and Economics, Vol. 26, No. 2, 375-390.
Demsetz, H. and Lehn, K., 1985, “The Structure of Corporate Ownership: Causes and Consequences,” Journal of Political Economy, Vol. 93, No. 6, 1155-1177.
Demsetz, H. and Villalonga, B., 2001, “Ownership Structure and Corporate Performance,” Journal of Corporate Finance, Vol. 7, No. 3, 209-233.
Denis, J. D., Denis, D. K., and Sarin, A., 1997, “Ownership Structure and Top Executive Turnover,” Journal of Financial Economics, Vol. 45, No. 2, 193-221.
Dharwadkar, B., George, G., and Brandes, P., 2000, “Privatization in Emerging Economies: An Agency Theory Perspective,” Academy of Management Review, Vol. 25, No. 3, 650-669.
Finkelstein, S. and Hambrick, D. C., 1990, “Top-management-team Tenure and Organizational Outcomes: The Moderating Role of Managerial Discretion,” Administrative Science Quarterly, Vol. 35, No. 3, 484-503.
Fischer, H. M. and Pollock, T. G., 2004, “Effects of Social Capital and Power on Surviving Transformational Change: The Case of Initial Public Offerings,” Academy of Management Journal, Vol. 47, No. 4, 463-481.
Forbes, D. P. and Milliken, F. J., 1999, “Cognition and Corporate Governance: Understanding Boards of Directors as Strategic Decision-making Groups,” Academy of Management Review, Vol. 24, No. 3, 489-505.
Garcia-Meca, E. and Sanchez-Ballesta, J. P., 2011, “Firm Value and Ownership Structure in the Spanish Capital Market,” Corporate Governance, Vol. 11, No. 1, 41-53.
Gedajlovic, E. R. and Shapiro, D. M., 1998, “Management and Ownership Effects: Evidence from Five Countries,” Strategic Management Journal, Vol. 19, No. 6, 533-553.
Grund, C. and Niels, W. N., 2005, “Age Structure of the Workforce and Firm Performance,” IZA Discussion Paper, No. 1816.
Hambrick, D. C. and Mason, P. A., 1984, “Upper Echelons: The Organization as A Reflection of Its Top Managers,” Academy of Management Review, Vol. 9, No. 2, 193-206.
Hambrick, D. C., 2007, “Upper Echelons Theory: An Update,” Academy of Management Review, Vol. 32, No. 2, 334-343.
Hannan, M. T. and Freeman, J., 1984, “Structural Inertia and Organizational Change,” American Sociological Review, Vol. 49, No. 2, 149-164.
Helwege, J., Pirinsky, C., and Stulz, R., 2007, “Why Do Firms Become Widely Held? An Analysis of the Dynamics of Corporate Ownership,” Journal of Finance, Vol. 62, No. 3, 995-1028.
Himmelberg, P., Hubbard, R. G., and Palia, D., 1999, “Understanding the Determinants of Managerial Ownership and the Link Between Ownership and Performance,” Journal of Financial Economics, Vol. 53, No. 3, 353-384.
Hu, H. W., Tam, O. K., and Tan, M. G. S., 2010, “Internal Governance Mechanisms and Firm Performance in China,” Asia Pacific Journal of Management, Vol. 27, No. 4, 727-749.
Jensen, M. C. and Meckling, W. H., 1976, “Theory of the Firm: Managerial Behavior, Agency Costs and Ownership Structure,” Journal of Financial Economics, Vol. 3, No. 4, 305-360.
Johnson, S. G., Schnatterly, K., and Hill, A. D., 2013, “Board Composition Beyond Independence: Social Capital, Human Capital, and Demographics,” Journal of Management, Vol. 39, No. 1, 232-262.
Johnson, R. A., Hoskisson, R. E., and Hitt, M. A., 1993. “Board of Director Involvement in Restructuring: the Effects of Board versus Managerial Controls and Characteristics,” Strategic Management Journal, Vol. 14, 33-50.
Kelly, D. and Amburgey, T. L., 1991, “Organizational Inertia and Momentum: A Dynamic Model of Strategic Change,” Academy of Management Journal, Vol. 34, No. 3, 591-612.
Kor, Y. Y. and Sundaramurthy, C., 2009, “Experience-based Human Capital and Social Capital of Outside Directors,” Journal of Management, Vol. 35, No. 4, 981-1006.
La Porta, R., Lopez-de-Silanes, F., and Shleifer, A., 1999, “Corporate Ownership Around the World,” Journal of Finance, Vol. 54, No. 2, 471-517.
Liu, C. H., 2015, “Network Position and Cooperation Partners Selection Strategies for Research Productivity,” Management Decision, Vol. 53, No. 3, 494-511.
McFadyen, M. A., Semadeni, M., and Cannella, A. A., 2009, “Value of Strong Ties to Disconnected Others: Examining Knowledge Creation in Biomedicine,” Organization Science, Vol. 20, No. 3, 552-564.
McConnell, J. J. and Servaes, H., 1990, “Additional Evidence on Equity Ownership and Corporate Value,” Journal of Financial Economics, Vol. 27, No. 2, 595-612.
Mitton, T., 2002, “A Cross-Firm Analysis of the Impact of Corporate Governance on the East Asian Financial Crisis,” Journal of Financial Economics, Vol. 64, No. 2, 215-241.
Morck, R., Wolfenzon, D., and Yeung, B., 2005, “Corporate Governance, Economic Entrenchment, and Growth,” Journal of Economic Literature, Vol. 43, No. 3, 655-720.
Murray, A. I., 1989, “Top Management Group Heterogeneity and Firm Performance,” Strategic Management Journal, Vol. 10, 125-141.
National Association of Corporate Directors, 1996, Report of the NACD Blue Ribbon Commission on Director Professionalism, Washington DC: NACD.
Perry-Smith, J. E. and Shalley, C. E., 2003, “The Social Side of Creativity: A Static and Dynamic Social Network Perspective.” Academy of Management Review, Vol. 28, No. 1, 89-106.
Salancik, G., 1977, “Commitment and Control of Organizational Behavior and Belief” in Staw, B. M. and Salancik, G. R. (eds.), New Directions in Organizational Behavior, Chicago: St. Claire Press, 1-54.
Sarkar, J. and Sarkar, S., 2009, “Multiple Board Appointments and Firm Performance in Emerging Economies: Evidence from India”, Pacific-Basin Finance Journal, Vol. 17, No. 2, 271-293.
Shleifer, A. and Vishny, R. W., 1986, “Large Shareholders and Corporate Control,” Journal of Political Economy, Vol. 94, No. 3, 461-488.
Shleifer, A. and Vishny, R. W., 1997, “A Survey of Corporate Governance,” Journal of Finance, Vol. 52, No. 2, 737-783.
Sturman, M. C., 2003, “Searching for the Inverted U-shaped Relationship between Time and Performance: Meta-analyses of the Experience/Performance, Tenure/Performance, and Age/Performance Relationships,” Journal of Management, Vol. 29, No. 5, 609-640.
Sundaramurthy, C. and Lewis, M., 2003, “Control and Collaboration: Paradoxes of Governance,” Academy of Management Review, Vol. 28, No. 3, 397-415.
Sosa, M. E., 2011, “Where Do Creative Interactions Come From? The Role of Tie Content and Social Networks,” Organization Science, Vol. 22, No. 1, 1-21.
Vafeas, N., 2003, “Length of Board Tenure and Outside Director Independence,” Journal of Business Finance and Accounting, Vol. 30, No. 7-8, 1043-1064.
Van Essen, M., Van Oosterhout, J. H., and Carney, M., 2012, “Corporate Boards and the Performance of Asian Firms: A Meta-analysis,” Asia Pacific Journal of Management, Vol. 29, No. 4, 873-905.
Villalonga, B. and Amit, R., 2006, “How Do Family Ownership, Control and Management Affect Firm Value?” Journal of Financial Economics, Vol. 80, No. 2, 385-417.
Westphal, J. D., and Bednar, M. K., 2005, “Pluralistic Ignorance in Corporate Boards and Firms’ Strategic Persistence in Response to Low Firm Performance,” Administrative Science Quarterly, Vol. 50, No. 2, 262-298.
Xiao, G., 2013, “Legal Shareholder Protection and Corporate R&D Investment,” Journal of Corporate Finance, Vol. 23, 240-266.
Yeh, Y. H., 2005, “Do Controlling Shareholders Enhance Corporate Value?” Corporate Governance: An International Review, Vol. 13, No. 2, 313-325.
Yeh, Y. H. and Woidtke, T., 2005, “Commitment or Entrenchment: Controlling Shareholders and Board Composition,” Journal of Banking and Finance, Vol. 29, No. 7, 1857-1885.
Young, M. N., Peng, M. W., Ahlstrom, D., Bruton, G. D., and Jiang, Y., 2008, “Corporate Governance in Emerging Economies: A Review of the Principal-Principal Perspective,” Journal of Management Studies, Vol. 45, No. 1, 196-220.
Zahra, S. A., Hayton, J. C., and Salvato, C., 2004, “Entrepreneurship in Family vs. Non-family Firms: A Resource-based Analysis of the Effect of Organizational Culture,” Entrepreneurship Theory and Practice, Vol. 28, No. 4, 363-381.
Zona, F., Zattoni, A., and Minichilli, A., 2013, “A Contingency Model of Boards of Directors and Firm Innovation: the Moderating Role of Firm Size,” British Journal of Management, Vol. 24, No. 3, 299-315.