本研究之主要目的是在探討多角化策略對其公司資金成本的影響，並且提供台灣公司對於多角化策略的決策參考。本文以2004年至2013年台灣所有上市櫃公司共4,048筆觀察值為樣本，並且使用多變量迴歸分析探討公司多角化的程度對於權益資金成本、負債資金成本與加權平均資金成本的影響。其結果均顯示多角化策略與公司資金成本無關聯性，公司多角化程度的大小並不能影響其資金成本，表示公司執行多角化策略並不能降低公司風險，使投資人要求較低的必要報酬率，降低公司的資金成本，皆隱含外部投資人並不相信公司可以透過多角化策略降低公司風險。

The main purpose of this study is to explore the relationship between diversification strategy and the cost of capital, and provide Taiwanese companies with advices while doing the diversification decision making. We obtain data from Taiwan Economic Journal (TEJ) database during the period of 2004 to 2013. The total sample is 4,048 firm-year observations. We employ multivariate regression analysis to analyze the degree of diversification strategy’s impact on cost of equity capital, cost of debt capital, and the weighted average cost of capital. The results show that the degree of diversification cannot affect corporate cost of capital, implying that stakeholders are not convinced by the risk reduction through firms’ diversification strategies.

Aggarwal, R.K., and Samwick, A.A. Why do managers diversify their firms? agency reconsidered. Journal of Finance, 58, (1), 71-118. (2003).
Amihud, Y., and Lev, B. Risk reduction as a managerial motive for conglomerate mergers. The Bell Journal of Economics, 12, (2), 605-617. (1981).
Amit, R., and Livnat, J. Diversification strategies, business cycles and economic performance. Strategic Management Journal, 9, (2), 99-110. (1988).
Ashbaugh-Skaife, H., Collins, D.W., and Kinney, W.R. The discovery and reporting of internal control deficiencies prior to SOX-mandated audits. Journal of accounting and economics, 44, (1), 166-192. (2007).
Avramov, D., Chordia, T., Jostova, G., and Philipov, A. Credit ratings and the cross-section of stock returns. Journal of Financial Markets, 12, (3), 469-499. (2009).
Berger, P.G., and Ofek, E. Diversification's effect on firm value. Journal of Financial Economics, 37, (1), 39-65. (1995).
Berry, C.H. Corporate growth and diversification. Journal of Law and Economics, 371-383. (1971).
Black, F. Capital market equilibrium with restricted borrowing. Journal of Business, 45, (3), 444-455. (1972).
Bowen, R.M., Xia, C., and Qiang, C. Analyst coverage and the cost of raising equity capital: evidence from underpricing of seasoned equity offerings. Contemporary Accounting Research, 25, (3), 657-699. (2008).
Brealey, R., and Myers, S. Principles of Corporate Finance, 6th edn. McGraw-Hill, New York. (2000).
Campbell, J.L., Dhaliwal, D.S., and Schwartz, W.C. Financing constraints and the cost of capital: evidence from the funding of corporate pension plans. Review of Financial Studies, 25, (3), 868-912. (2012).
Carter, J.R. In search of synergy: a structure-performance test. Review of Economics and Statistics, 59, (3), 279. (1977).
Comment, R., and Jarrell, G.A. Corporate focus and stock returns. Journal of Financial Economics, 37, (1), 67-87. (1995).
Cummins, J.D., and Phillips, R.D. Estimating the cost of equity capital for property-liability insurers. Journal of Risk and Insurance, 72, (3), 441-478. (2005).
Das, R., and Mohanty, B. Choosing a diversification project in a regulated economy. Long Range Planning, 14, (2), 78-86. (1981).
Demirkan, S., Radhakrishnan, S., and Urcan, O. Discretionary accruals quality, cost of capital, and diversification. Journal of Accounting, Auditing and Finance, 27, (4), 496-526. (2012).
Denis, D.J., Denis, D.K., and Sarin, A. Agency problems, equity ownership, and corporate diversification. The Journal of Finance, 52, (1), 135-160. (1997).
Dhaliwal, D. S., Gleason, C. A., Heitzman, S., and Melendrez, K. D. Auditor Fees and Cost of Debt. Journal of Accounting, Auditing and Finance, 23, (1), 1. (2008).
Erdorf, S., Hartmann-Wendels, T., Heinrichs, N., and Matz, M. Corporate diversification and firm value: a survey of recent literature. Financial Markets and Portfolio Management, 27, (2), 187-215. (2013).
Fama, E.F., and French, K.R. The cross‐section of expected stock returns. The Journal of Finance, 47, (2), 427-465. (1992).
Francis, J. R., Khurana, I. K., and Raynolde, P. Disclosure incentives and effects on cost of cpital around the World. The Accounting Review, 80, (4). 1125. (2005).
Graham, J.R., and Harvey, C.R. The theory and practice of corporate finance: evidence from the field. Journal of Financial Economics, 60, (2–3), 187-243. (2001).
Hill, C.W.L. Diversified growth and competition: the experience of twelve large UK firms. Applied Economics, 17, (5), 827. (1985).
Jacquemin, A.P., and Berry, C.H. Entropy measure of diversification and corporate growth. The Journal of Industrial Economics, 27, (4), 359-369. (1979).
Jensen, M.C. Agency cost of free cash flow, corporate finance, and takeovers. Corporate Finance, and Takeovers. American Economic Review, 76, (2). (1986).
Jensen, M.C., and Meckling, W.H. Theory of the firm: managerial behavior, agency costs and ownership structure. Journal of Financial Economics, 3, (4), 305-360. (1976).
Jensen, M.C., and Murphy, K.J. Performance pay and top-management incentives. Journal of Political Economy, 98, (2), 225-264. (1990).
Kabir, R., Li, H., and Veld-Merkoulova, Y.V. Executive compensation and the cost of debt. Journal of banking and finance, 37, (8), 2893-2907. (2013).
Khanna, T., and Palepu, K. Is group affiliation profitable in emerging markets? an analysis of diversified Indian business groups. Journal of Finance, 55, (2), 867-891. (2000).
Kuppuswamy, V., Serafeim, G., and Villalonga, B. The effect of institutional factors on the value of corporate diversification. Working Paper. (2012).
Lamont, O.A., and Polk, C. Does diversification destroy value? evidence from the industry shocks. Journal of Financial Economics, 63, (1), 51-77. (2002).
Lang, L.H.P., and Stulz, R.M. Tobin's q, corporate diversification, and firm performance. Journal of Political Economy,102, (6). 1248-1280. (1994).
Lewellen, W.G. A pure financial rationale for the conglomerate merger. The Journal of Finance, 26, (2), 521-537. (1971).
Maksimovic, V., and Phillips, G. Do conglomerate firms allocate resources inefficiently across industries? theory and evidence. Journal of Finance, 57, (2), 721-767. (2002).
Mansi, S.A., and Reeb, D.M. Corporate diversification: what gets discounted? Journal of Finance, 57, (5), 2167-2183. (2002).
Martin, J.D., and Sayrak, A. Corporate diversification and shareholder value: a survey of recent literature. Journal of Corporate Finance, 9, (1), 37-57. (2003).
Matsusaka, J.G., and Nanda, V. Internal capital markets and corporate refocusing. Journal of Financial Intermediation, 11, (2), 176-211. (2002).
Meyer, M., Milgrom, P., and Roberts, J. Organizational prospects, influence costs, and ownership changes. Journal of Economics and Management Strategy, 1, (1), 9-35. (1992).
Montgomery, C.A. Product-market diversification and market power. Academy of Management Journal, 28, (4), 789-798. (1985).
Montgomery, C.A. Corporate diversification. The Journal of Economic Perspectives, 8, (3), 163-178. (1994).
Nguyen, T.H., Séror, A., and Devinney, T.M. Diversification strategy and performance in Canadian manufacturing firms. Strategic Management Journal, 11, (5), 411. (1990).
Palepu, K. Diversification strategy, profit performance and the entropy measure. Strategic Management Journal, 6, (3), 239-255. (1985).
Pittman, J.A., and Fortin, S. Auditor choice and the cost of debt capital for newly public firms. Journal of accounting and economics, 37, (1), 113-136. (2004).
Rajan, R., Servaes, H., and Zingales, L. The cost of diversity: the diversification discount and inefficient investment. The Journal of Finance, 55, (1), 35-80. (2000).
Rumelt, R.P. Diversification strategy and profitability. Strategic Management Journal, 3, (4), 359-369. (1982).
Scharfstein, D.S. The dark side of internal capital markets II: evidence from diversified conglomerates. Working Paper. (1998).
Shin, H.-H., and Stulz, R.M. Are internal capital markets efficient? The Quarterly Journal of Economics, 113, (2), 531-552. (1998).
Shleifer, A., and Vishny, R.W. Management entrenchment: the case of manager-specific investments. Journal of Financial Economics, 25, (1), 123-139. (1989).
Shleifer, A., and Vishny, R.W. The Takeover wave of the 1980s. Science, 249, (4970), 745-749. (1990).
Singh, M., Davidson III, W.N., and Suchard, J.-A. Corporate diversification strategies and capital structure. The Quarterly Review of Economics and Finance, 43, (1), 147-167. (2003).
Stein, J.C. Internal capital markets and the competition for corporate resources. Journal of Finance, 52, (1), 111-133. (1997).
Stulz, R. Managerial discretion and optimal financing policies. Journal of Financial Economics, 26, (1), 3-27. (1990).
Teece, D.J. Economies of scope and the scope of the enterprise. Journal of Economic Behavior and Organization, 1, (3), 223-247. (1980).
Villalonga, B. Diversification discount or premium? new evidence from the business information tracking series. The Journal of Finance, 59, (2), 479-506. (2004).