本論文的研究目的是想了解什麼因素驅動臺灣上市公司董監事股票質押的行為。有些董監事至始不會進行股票質押，但有些會，而且有的持續高質押，他們行為的不同是因為什麼呢?而且在現今的環境裡，高質押比率已被視為掏空公司的警訊，為何有些董監事還持續高質押比率呢?以前的文獻都著重研究董監事質押比率的結果，而本文著重於探討可能的因素影響董監事股票質押的行為。
我們以2000到2012年在台灣上市公司的年資料為實證研究樣本，資料皆從台灣經濟新報財經資料庫中獲取。我們先把樣本挑出董監事持續13年末都有質押與沒有的公司的兩組子樣本進行比較，使用logit模型，之後再利用tobit模型對總樣本進行三方面因素的探討，皆分別從公司特性、股價與公司治理角度解釋衡量，而使用兩種模型能強化結果，排除統計上的問題。
主要實證結果顯示，公司特性、股價與公司治理的確與董監事的質押持股行為有關，另外還發現到身為公司債權人的銀行，具有監督效果，能降低董監事的質押持股行為所產生的代理問題，此外藉由TEJ資料庫對集團控制型態的分類，發現到家族控制型態比起專業經理人控制型態更會進行質押持股行為。
最後本論文的實證結果支持在有董監事持股質押行為的公司，其公司治理要素較沒有此行為的公司容易產生控制股東與小股東之間的代理問題，使控制股東更有能力利用質押持股行為達到剝削小股東以利己的目標。

In this paper, we investigate what determine share pledging behavior of the directors and supervisors. What give them incentives to do different behavior, some directors and supervisors never do share collateral, others continue doing and still others pledge high shares? Nowadays, the high share pledge ratio which has been considered as a warning that tells us that someone is hollowing out company's assets, is still done by the directors and supervisors. Why is that? Most of previous studies focus on the consequences of shares pledging behavior rather than the causes of shares pledging behavior. This paper attempts to provide the factors of directors and supervisors’ share collateralization.
This paper uses the data of Taiwanese publicly listed companies from the Taiwan Economic Journal (TEJ) database from 2000 to 2012. Firstly, we use logit model to assess whether independent variables are suitable with subsample which are pledging shares for 13 year-end and non-pledging shares for 13 year-end. Then, we use tobit model to assess with full sample. Both are used to measure and explain variables from three perspective: firm characteristics, stock price and corporate governance. And it can stronger the results and remove the error of the results which are caused by incorrect statistical method by using two different models.
Our empirical results indicate that shares pledging behavior of the directors and supervisors has connections with firm characteristics, stock price and corporate governance. The research findings also indicate that the existence of supervision of creditors of the firms helps with reducing agency problem. In addition, we use the types of control of business groups data constructed by TEJ and find that the family control type which compared with the professional manager control is more likely to do shares pledging behavior.
Finally, our empirical results support corporate governance in the firms which have shares pledging behavior of the directors and supervisors is easier causing agency problem between controlling shareholders and minority shareholders than in the firms which have no shares pledging behavior of the directors and supervisors. Controlling shareholders could have more power to gain the interests from exploiting minority shareholders by pledging shares.

Berle, A., and G. Means, 1932, The Modern Corporation and Private Property (Macmillan, New York).
Bunkanwanicha, P., J. Gupta, and R. Rokhim, 2008, Debt and Entrenchment: Evidence from Thailand and Indonesia, European Journal of Operational Research 185, 1578-1595.
Burkart, M., D. Gromb, and F. Panunzi, 1998, Why Higher Takeover Premia Protect Minority Shareholders, Journal of Political Economy 106, 172-204.
Chan, K., Chen, Hung-Kun, Hu, Shing-yang, and Liu, Yu-Jane, 2013, Shares Pledged and Corporate Repurchase☆.
Chen, A., and L. Kao, 2011, Effect of Collateral Characteristics on Bank Performance: Evidence from Collateralized Stocks in Taiwan, Journal of Banking & Finance 35, 300-309.
Chen, Yi-Kai., A. Chen, and Kao, Lanfeng, 2007, Agency Costs of Controlling Shareholders' Share Collateral with Taiwan Evidence, Review of Pacific Basin Financial Markets and Policies 10, 173-191.
Claessens, S., S. Djankov, and L. H. P. Lang, 2000, The Separation of Ownership and Control in East Asian Corporations, Journal of Financial Economics 58, 81-112.
Claessens, S., D. Simeon, J. P. H. Fan, and L. H. P. Lang, 2002, Disentangling the Incentive and Entrenchment Effects of Large Shareholdings, The Journal of Finance 57, 2741-2771.
Cook, D. O., L. Krigman, and J. C. Leach, 2004, On the Timing and Execution of Open Market Repurchases, Review of Financial Studies 17, 463-498.
Demsetz, H., 1983, The Structure of Ownership and the Theory of the Firm, Journal of Law and Economics 26, 375-390.
Demsetz, H., and K. Lehn, 1985, The Structure of Corporate Ownership: Causes and Consequences, Journal of Political Economy 93, 1155-1177.
Dharwadkar, R., G. George, and P. Brandes, 2000, Privatization in Emerging Economies: An Agency Theory Perspective, The Academy of Management Review 25, 650-669.
Eisenberg, M. A., 1976, The Structure of the Corporation: A Legal Analysis (Beard Books.
Faccio, M., and L. H. P. Lang, 2002, The Ultimate Ownership of Western European Corporations, Journal of Financial Economics 65, 365-395.
Ginglinger, E., and J. Hamon, 2007, Actual Share Repurchases, Timing and Liquidity, Journal of Banking & Finance 31, 915-938.
Hill, C. W. L., and T. M. Jones, 1992, Stakeholder-Agency Theory, Journal of Management Studies 29, 131-154.
Jensen, M. C., 1986, Agency Costs of Free Cash Flow, Corporate Finance, and Takeovers, American Economic Review 76, pp. 323–329.
Jensen, M. C., and W. H. Meckling, 1976, Theory of the Firm: Managerial Behavior, Agency Costs and Ownership Structure, Journal of Financial Economics 3, 305-360.
Jensen, M. C., and R. S. Ruback, 1983, The Market for Corporate Control: The Scientific Evidence, Journal of Financial Economics 11, 5-50.
John, K., and L. W. Senbet, 1998, Corporate Governance and Board Effectiveness, Journal of Banking & Finance 22, 371-430.
Kao, L., Chiou, Jeng-Ren, and A. Chen, 2004, The Agency Problems, Firm Performance and Monitoring Mechanisms: The Evidence from Collateralised Shares in Taiwan, Corporate Governance: An International Review 12, 389-402.
La Porta, R., Florencio Lopez‐de‐Silanes, Andrei Shleifer, and Robert W. Vishny, 1998, Law and Finance, Journal of Political Economy 106, 1113-1155.
La Porta, R., F. Lopez-De-Silanes, and A. Shleifer, 1999, Corporate Ownership around the World, The Journal of Finance 54, 471-517.
Lee, Tsun-Siou, and Yeh, Yin-Hua, 2004, Corporate Governance and Financial Distress: Evidence from Taiwan, Corporate Governance: An International Review 12, 378-388.
Leland, H. E., and D. H. Pyle, 1977, Informational Asymmetries, Financial Structure, and Financial Intermediation, The Journal of Finance 32, 371-387.
Lins, K. V., 2003, Equity Ownership and Firm Value in Emerging Markets, Journal of Financial & Quantitative Analysis 38, 159-184.
Morck, R., A. Shleifer, and R. W. Vishny, 1988, Management Ownership and Market Valuation: An Empirical Analysis, Journal of Financial Economics 20, 293-315.
Morck, R., D. Wolfenzon, and B. Yeung, 2005, Corporate Governance, Economic Entrenchment, and Growth, Journal of Economic Literature 43, 655-720.
Paligorova, T., and Z. Xu, 2012, Complex Ownership and Capital Structure, Journal of Corporate Finance 18, 701-716.
Porta, R. L., F. Lopez-de-Silanes, A. Shleifer, and R. Vishny, 2002, Investor Protection and Corporate Valuation, The Journal of Finance 57, 1147-1170.
Shleifer, A., and R. W. Vishny, 1986, Large Shareholders and Corporate Control, Journal of Political Economy 94, 461-488.
Shleifer, A., and R. W. Vishny, 1997, A Survey of Corporate Governance, The Journal of Finance 52, 737-783.
Yeh, Yin-Hua, 2005, Do Controlling Shareholders Enhance Corporate Value?, Corporate Governance: An International Review 13, 313-325.
Yeh, Yin-hua, Ko, Chen-en, and Su, Yu-Hui, 2003, Ultimate Control and Expropriation of Minority Shareholders: New Evidence from Taiwan, Academia economic papers 31, 263.
Yeh, Yin-hua, Lee, Tsun-siou, and T. Woidtke, 2001, Family Control and Corporate Governance: Evidence from Taiwan, International Review of Finance 2, 21-48.
Yeh, Yin-hua, and T. Woidtke, 2005, Commitment or Entrenchment?: Controlling Shareholders and Board Composition, Journal of Banking & Finance 29, 1857-1885.
Young, Chaur-Shiuh, Tsai, Liu-Ching. Tsai, and Hsieh, Pei-Gin, 2008, Voluntary Appointment of Independent Directors in Taiwan: Motives and Consequences, Journal of Business Finance & Accounting 35, 1103-1137.
Young, M. N., M. W. Peng, D. Ahlstrom, G. D. Bruton, and Y. Jiang, 2008, Corporate Governance in Emerging Economies: A Review of the Principal–Principal Perspective, Journal of Management Studies 45, 196-220.