本研究之目的主要探討多角化的公司是否有代理成本的問題。為此，我們選擇美國2002-2007年的樣本，有別於先前學者的研究方法，我們使用兩個衡量指標去檢測多角化公司隱含的代理成本問題:分別是CEO週轉率和CEO薪酬。實證結果發現多角化的公司中CEO週轉率和公司績效的關連性較低，且多角化的公司中CEO的薪酬和公司績效的關連性較弱。此外，我們分別使用四個績效衡量指標去重複驗證我們的實證。綜合我們的研究，實證結果支持我們的假設多角化的公司存在代理成本的問題。

This study examines whether diversified firms have principal-agent problem. In this paper, we illustrate a different approach to test these issues for U.S. sample during the period of 2002-2007. We select two measures to examine agency implication of diversification: CEO turnover and CEO compensation. We find that: CEO turnover is less sensitive to firm performance for diversified firms, and pay-performance sensitivity is weaker for diversified firms. Additionally, our results are robust to alternative measures of corporate performance. Taken together, our results support the argument that diversified firms are characterized by severe agency conflicts.

Aggarwal, R. and A. Samwick (2003). "Why do managers diversify their firms? Agency reconsidered." Journal of Finance: 71-118.
Amihud, Y. and B. Lev (1981). "Risk reduction as a managerial motive for conglomerate
mergers." The Bell Journal of Economics: 605-617.
Barkema, H. and L. Gomez-Mejia (1998). "Managerial compensation and firm performance: A general research framework." Academy of Management Journal: 135-145.
Berger, P. and E. Ofek (1995). "Diversification's effect on firm value." Journal of Financial Economics: 39-65.
Berry, T., J. Bizjak (2000) "CEO turnover and firm diversification."Working Paper.
Campa, J. and S. Kedia (2002). "Explaining the diversification discount." Journal of Finance: 1731-1762.
Conyon, M. and G. Sadler (2001). "Executive pay, tournaments and corporate performance in UK firms." International Journal of Management Reviews: 141-168.
Dahya, J., J. McConnell (2002). "The Cadbury Committee, corporate performance, and top management turnover." Journal of Finance: 461-483.
Defond, M. and M. Hung (2004). "Investor protection and corporate governance: Evidence from worldwide CEO turnover." Journal of Accounting Research:
Denis, D., D. Denis (1997). "Agency problems, equity ownership, and corporate diversification." Journal of Finance: 135-160.
Denis, D., D. Denis (2002). "Global diversification, industrial diversification, and firm value." Journal of Finance: 1951-1979.
Fama, E. and K. French (1993). "Common risk factors in the returns on stocks and bonds." Journal of Financial Economics: 3-56.
Firth, M., P. Fung (2006). "Corporate performance and CEO compensation in China." Journal of Corporate Finance: 693-714.
Garen, J. (1994). "Executive compensation and principal-agent theory." Journal of political economy: 1175-1199.
Houston, J. and A. Naranjo (2003). "Capital market development, international integration, legal systems, and the value of corporate diversification: a cross-country analysis." Journal of Financial and Quantitative Analysis: 135-157.
Jensen, M. (1986). "Agency costs of free cash flow, corporate finance, and takeovers." The American Economic Review: 323-329.
Jensen, M. and K. Murphy (1990). "Performance pay and top-management incentives." Journal of political economy: 225.
Kang, J. and A. Shivdasani (1995). "Firm performance, corporate governance, and top executive turnover in Japan." Journal of Financial Economics: 29-58.
Kaplan, S. (1994). "Top executives, turnover, and firm performance in Germany." Journal of Law, Economics, and Organization: 142-159.
Kato, T. and K. Kubo (2006). "CEO compensation and firm performance in Japan: Evidence from new panel data on individual CEO pay." Journal of the Japanese and International Economies: 1-19.
Kesner, I. and T. Sebora (1994). "Executive succession: Past, present & future." Journal of Management: 327.
Khanna, T. and K. Palepu (2000). "Is group affiliation profitable in emerging markets? An analysis of diversified Indian business groups." Journal of Finance: 867-891.
Lang, L. and R. Stulz (1994). "Tobin's q, corporate diversification, and firm performance." Journal of political economy: 1248.
Lel U. and D. Miller (2008). "International cross-listing, firm performance and top management turnover: A test of the bonding hypothesis." Journal of Finance:1897-1937.
Lins, K. and H. Servaes (1999). "International evidence on the value of corporate diversification." Journal of Finance: 2215-2239.
Rose, N. and A. Shepard (1997). "Firm diversification and CEO compensation: Managerial ability or executive entrenchment?" Rand Journal of Economics: 489-514.
Shleifer, A. and R. Vishny (1989). "Management entrenchment." Journal of Financial Economics: 123-139.