本研究欲從公司治理的角度探討多重董監事及企業多角化與公司價值間的關係，並分析公司特性及董監事特性等變數對公司價值的影響。此外，再將樣本區分為多角化公司以及非多角化公司，以實證公司治理相關特性對於公司價值的影響是否有顯著的差異。由於不同公司間的資料有異質性存在，所以在用普通最小平方法進行求解時，同時採用White (1980)的異質一致性估計式(heteroscedasticity consistent estimator)來調整參數估計值之標準誤，以提高假設檢定之一致性。
實證結果顯示董監事的忙碌程度對公司價值有正向的影響，總資產、負債比例、息前稅前盈餘比例、資本支出比例及外部董監事的比例與公司價值有負向且顯著的影響；而董事會規模及領導結構則與公司價值有正向且顯著的影響，另外在樣本區分為多角化公司與非多角化公司之後發現，以多角化公司作為樣本所得到之實證結果和全樣本的結果相仿，但若以非多角化公司為樣本時發現大部分的變數都與公司價值沒有顯著的影響。

This study examines how multiple directorships and diversification affect firm value on the basis of corporate governance. Besides, I also analyze the impacts of firm and board characteristics on firm value. In addition, the samples are classified into diversified and non-diversified firms to explore if the effects of corporate governance related characteristics on firm value are different significantly. Due to the existence of heterogeneity among individual firm, this study adopt heteroscedasticity consistent estimator (White, 1980) to adjust the estimated standard deviation of parameters in order to improve the consistence of test when using ordinary least squares to proceed.
The results show that the busyness of directorships has positive effect to firm value. Total assets, debt ratio, EBIT ratio, capital ratio and the percentage of outsider directorships have negative and significant impact to firm value. Board size and CEO duality have positive and significant influence to firm value. Besides, when the samples are divided into diversified and non-diversified firms, the empirical results of diversified firms are similar to thst of the whole samples. In contrast, when the samples belong to non-diversified firms, most explanatory variables have no significant effect on firm value.

中文
余宗翰，「國際化與多角化對績效影響之研究—以國內食品廠商為例」，實踐大學企業管理研究所碩士論文，民國92年
林秀倩，「財務槓桿對於多角化企業價值之再探討」，政治大學財務管理研究所碩士論文，民國92年
林振昌，「營造業多角化經營關鍵因素之探討」，中華大學營建管理研究所碩士論文，民國96年
唐人璠，「企業多角化內部創業經營策略之研究—以電信工程部門為例」，中山大學企業管理學系碩士論文，民國92年
浦筱德，「集團企業的多角化與資源整合管理機制的探討—以太平洋建設集團為例」，中山大學高階經營碩士學程專班碩士論文，民國90年
黃晉偉，「多角化海外投資對台灣製造業經營績效的影響」，東吳大學經濟學系碩士論文，民國94年
黃子菱，「集團企業多角化程度與經營績效相關性之研究—以平衡計分卡觀點探討」，東吳大學會計學系碩士論文，民國91年
彭成勝，「多角化策略與經營績效之研究—以興農集團為例」，中正大學企業管理研究所碩士論文，民國94年
彭智強，「多角化與國際化策略配合對企業經營績效關係之研究—以技術生命週期觀點分析之」，中原大學企業管理學系碩士論文，民國92年
楊智元，「多角化經營能否降低非系統風險？」，輔仁大學金融研究所碩士論文，民國92年
葉銀華，「家族控股集團與股票報酬共變性之實證研究」，台大管理論叢，第九卷第一期，民國87 年，25-49 頁
蘇怡如，「台灣集團企業多角化程度之探討」，成功大學國際企業研究所碩士論文，民國91年
蘇姵伊，「家族控股企業之多角化經營決策：以台灣上市公司為例」，朝陽科技大學財務金融系碩士論文，民國96年
英文
Aaker, D. A. 1984. “Strategic Market Management.” New York, John Wiely and Sons Inc.
Aaler, D. A. 1995. “Strategic Market Management.” 4th ed. New York, John Wiely and Sons Inc.
Ahn, S., and Denis, D. J. 2004. “Internal capital markets and investment policy: evidence from corporate spinoffs.” Journal of Financial Economics, 71, 489-576.
Ahn, S., Denis, D. J., and Denis, D. K. 2006. “Leverage and investment in diversified firms.” Journal of Financial Economics, 79, 317-337.
Amihud, Y., and Lev, B. 1981. “Risk Reduction as a Managerial Motive for Conglomerate Mergers.” Bell Journal of Economics, 12, 605-617.
Amit, R., and Livnat, J. 1988. “Diversification Strategies, Business Cycle, and Economic Performance.” Strategic Management Journal, 9, 99-110.
Amit, R., and Livnat, J. 1988. “Diversification and Risk-return Trade-off.” Acadeny of Management Journal, 31, 154-166.
Ansoff, H. I. 1957. “Strategics for Diversification.” Harvard Business Review.35, 113-124.
Ansoff, H. I. 1965. “Corporate Strategy; An Analytic Approach to Business Policy for Growth and Expansion.” New York, McGraw-Hill.
Bacon, 1990. “Membership and Organization of Corporate Boards.” Research Report No. 922.
Balck, 1998. “Shareholder Activism and Corporate Governance in the United States.” In P. Newman, ed: The New Pal grave Dictionary of Economics and the Law.
Barney, J. B. 1997. “Gaining and Sustaining Competitive Advantage.” New York, Addition-Wesley Publishing Company.
Baysinger, and Hoskisson 1990. “The Composition of Boards of Directors and Strategic Control: Effects on Corporate Strategy.” Acadeny of Management Review, 15, 72-87.
Beattie, D. L. 1980. “Conglomerate Diversification and Performance: a Survey and Time Series Analysis.” Applied Economics, 251-273.
Beiner, S., and Schmid, M. M. 2005. “Agency Conflicts, Corporate Governance, and Corporate Diversification—Evidence from Switzerland.” Unpublished manuscript, New York Universuty.
Berger, P. G., and Ofek, E. 1995. “Diversification’s Effect on Firm Value.” Journal of Financial Economic, 37, 39-65.
Berry, C. H. 1975. “Corporate Growth and Diversification.” Princeton, NJ, Princeton University Press.
Bhagat, S., Carey, D., and Elson, C. 1999. “Director Ownership, Corporate Performance, and Management Turnover.” Business Lawyer, 54, 885-919.
Booz, Allen and Hamilton 1985. “Diversification: A Survey of European Chief Executives.” Booz, Allen and Hamilton, Inc., New York.
Bradley, M. A., Desai, A., and Han Kim, E. 1998. “Synergistic Gains from Corporate Acquisitions and Their Division between the Stockholders of Target and Acquiring Firms.” Journal of Financial Economics, 21, 2-40.
Chandler, A. D. 1962. “Strategy and Structure: Chapters in the History of the American Industrial Enterprise.” Cambridge, MA, MIT Press.
Comment, R., and Jarrell, G. 1995. “Corporate Focus and Stock Returns.” Journal of Financial Economics, 37, 67-88.
Core, J., Holthausen, R., and Larcker, D. 1999. “Corporate Governance, Chief Executive Officer Compensation, and Firm Performance.” Journal of Financial Economics, 51, 371-406.
Council of Institutional Investors, 2003. Core Policies, Positions and Explanatory Notes.
Das, R., and Mohanty, B. 1981. “Choosing a Diversification Project in a Regulated Economy.” LongRange Planning, 14, 78-86.
Dittmar, A., and Shivdasani, A. 2003. “Divestitures and Divisional Investment Policies.” Journal of Finance, 58, 2711-2744.
Eisenberg, T., Sundgren, S., and Wells, M. 1997. “Larger Board Size and Decreasing Firm Value in Small Firms.” Journal of Financial Economics, 48, 35-54.
Fama, E. 1980. “Agency Problems and the Theory of the Firm.” Journal of Political Economy, 88, 288-303.
Fama, E., and Jensen, M. 1983. “The Separation of Ownership and Control.” Journal of Law and Economics, 26, 301-325.
Ferris, S., Jagannathan, M., and Pritchard, A. C. 2003. “Too Busy to Mind the Business? Monitoring by Directors with Multiple Board Appointments.” Journal of Finance, 59, 1087-1111.
Fich, E., and Shivdasani, A. 2006. “Are Busy Boards Effective Monitors.” Journal of Finance, 61, 689-724.
Gertner, R., Powers, E., and Scharfstein, D. 2002. “Learning about Internal Capital Markets from Corporate Spinoffs.” Journal of Finance, 57, 2479-2506.
Gillan, and Starks 1998. “A Survey of Shareholder Activism: Motivation and Empirical Evidence.” Contemporary Finance Digest, 2, 1-26.
Glueck, W. F. 1976. “Business Policy: Strategic Formation and Management Action.” 2nd ed., New York, McGraw-Hill.
Gort, M. 1962. “Diversification and Integration in American Industry.” Princeton, National Bureau of Economic Research.
Graham, J. R., Lemmon, M., and Wolf, J. 2002. “Does Corporate Diversification Destroy Value.” Journal of Finance, 59, 695-720.
Hill, C. W. L., and Hoskisson, R. E. 1987. “Strategy and Structure in the Multiproduct Firm.” Academy of Management Review, 12, 331-341.
Hoskisson, R. E., and Hitt, M. A. 1990. “Antecedents and Performance Outcomes of Diversification: A Review and Critique of Theoretical Outcomes of Diversification.” Journal of Management, 16, 461-509.
Huson, Parrino, and Starks 2001. “Internal Monitoring Mechanisms and CEO Turnover: a Long-Term Perspective.” Journal of Finance, 56, 2265-2297.
Jarrell, Gregg, Brickley, James, Netter, and Jeffrey 1988. “The Market for Corporate Control: the Empirical Evidence since 1980.” Journal of Economic Perspectives, 2, 49-68.
Jauch, L. R., and Glueck, W. F. 1988. “Strategic Management and Business Policy.” New York McGraw-Hill, Inc.
Jayati, S., and Subrata, S. 2008. “Multiple Board Appointments and Firm Performance in Emerging Economies: Evidence from India.” Pacific-Basin Finance Journal, 2, 1-23.
Jensen, M. C. 1986. “Agency Costs of Free Cash Flow, Corporate Finance, and Takeovers.” American Economic Review, 76, 323-329.
Jensen, M., and Ruback, R. 1983. “The Market for Corporate Control: the Scientific Evidence.” Journal of Financial Economics, 11, 5-50.
Jensen, M. C., and Meckling W. 1976. “Theory of the Firm: Managerial Behavior, Agency Costs and Ownership Structure.” Journal of Financial Economics, 3, 305-360.
Jiraporn, P., Kim, Y. S., Davidson, W. N., and Singh, M. 2006. “Corporate Governance, Shareholder Rights, and Firm Diversification: an Empirical Analysis.” Journal of Banking and Finance, 30, 947-963.
Jiraporn, P., Kim, Y. S., and Davidson, W. N. 2008. “Multiple Directorships and Corporate Diversification.” Journal of Empirical Finance, 15, 418-435.
Jiraporn, P., DaDalt, P., Ning, Y., and Davidson, W. N. 2007. “Too Busy To Show Up? An Analysis of Directors’ Absences.” Working paper. School of Graduate Professional Studies, Pennsylvania State University.
Kamien, M. I., and Schwartz, N. L. 1975. “Market Structure and Innovation: A Survey.” Journal of Economic Literrature, 13, 1-37.
Karpoff, 1999. “The Impact of Shareholder Activism on Target Companies: a Survey of Empirical Findings.” Unpublished Manuscript, University of Washington.
La Porta, R., Lopez-de-Silanes, F., Shleifer, A., and Vishny, R.W. 2000. “Investor Protection and Corporate Governance.” Journal of Financial Economics, 58, 3-27.
Lang, L. H. P., and Stulz, R. 1994. “Tobin’s Q, Corporate Diversification, and Firm Performance.” Journal of Political Economy, 102, 1248-1280.
Lewellen, W. 1971. “A Pure Financial Rationale for the Conglomerate Merger.” Journal of Finance, 26, 521-537.
Loderer, C., and Martin, K. 1990. “Corporate Acquisitions by Listed Firms: the Experience of a Comprehensive Sample.” Financial Management, 19, 17-33.
Mace, M. 1986. “Directors: Myth and Reality.” Harvard University Press, Boston, MA.
Miller A., and Dess, G. G. 1996. “Strategic Management.” New York, McGraw-Hill.
National Association of Corporate Directors, 1996. NACD Blue Ribbon Commission Report on Director Professionalism.
Oster, S. M. 1994. “Modern Competitive Analysis.” 2nd ed., Oxford University Press, New York, Oxford.
Perry, T., and Peyer, U. 2005. “Board Seat Accumulation by Executives: a Shareholder’s Perspective.” Journal of Finance, 60, 2083-2123.
Pitts, R. A., and Hopkins, D. H. 1982 “Firm Diversity: Conceptualization and Measurement.” Academy of Management Journal, 7, 620-629.
Ramanujam, R., and Varadarajan, P. 1989 “Research on Corporate Diversification: A Synthesis.” Strategy Management Journal, 10, 523-551.
Reed, R., and Luffman, G. A. 1986 “Diversification: The Growing Confusion.” Strategic Management Journal, 15, 29-35.
Rosenstein, and Wyatt 1997. “Inside Directors, Board Effectiveness, and Shareholder Wealth.” Journal of Financial Economics, 44, 229-250
Rumelt, R. P. 1974. “Strategy, Structure, and Economic Performance.” Cambridge, MA, Harvard University Press.
Shivdasani, A., and Yermack, D. 1999. ”CEO Involvement in the Selection of New Board Members: an Empirical Analysis.” Journal of Finance, 54, 1829-1853.
Singh, and Harianto 1989. “Management-Board Relationships, Takeover Risk, and the Adoption of Golden Para Chutes.” Academy of Management Journal, 32, 7.
Stulz, R. 1990 “Managerial Discretion and Optimal Financial Policies.” Journal of Financial Economics, 26, 3-27.
Teece, D. J. 1982 “Towards and Economic Theory of the Multiproduct Firms.” Journal of Economic Behavior and Organization, 3, 39-63.
Weisbach, 1988. “Outside Directors and CEO Turnover.” Journal of Financial Economics, 20, 431-460.
White, H. 1980. “A Heteroskedasticity-Consistent Covariance Matrix Estimator and a Direct Test for Heteroskedasticity”
Whited, Toni, 2001. “Is it Efficient Investment that Causes the Diversification Discount.” Journal of Finance, 56, 1667-1692.
Wrigley, L. 1970. “Divisional Autonomy and Diversification.” Unpublished doctoral dissertation, Harvard Business School.
Yang, L. 2005. “What has Motivated Diversification? Evidence from Corporate Governance.” Unpublished manuscript, University of Maryland.
Yermack, D. 1996. “A Higher Market Valuation of Companies with a Small Board of Directors.” Journal of Financial Economics, 40, 185-205.
Zahra, and Pearce 1989. “Boards of Directors and Corporate Financial Performance: a Review and Integrative Model.” Journal of Management, 15, 291.