台灣公司治理評鑑系統對市場評價之關係以前百分之五評選績優之企業為例

Abstract

自從安隆事件及亞洲金融風暴後，公司治理（Corporate Governance）已成為國際間熱門而普及的研究課題。公司治理是一種指導及管理企業的機制，其主要目標是提高企業經營管理之效能與監督管理者的行為，藉此保障股東、債權人及其他利害關係人的合法權益，同時促使企業落實應盡之社會責任。 我國從二〇〇二年開始逐步導入公司治理概念，但後續發生的太電案（2003）、博達案（2004）及力霸掏空案（2007）都顯示了我國在公司治理觀念的薄弱，近期的高雄排放汙水事件、化學管線氣爆事件及後續之相關食品安全風暴，再次顯示了我國公司治理成效不彰，同時提醒我們公司治理的重要性。 相較於鄰近其他亞洲國家公司治理改革之迅速發展，為了因應及加速與國際接軌，二〇一三年由金融監督管理委員會提出了「強化我國公司治理藍圖」，其中更將「公司治理評鑑」列為其重點之具體措施。 我國已完成兩屆公司治理評鑑，本研究以事件研究法來探討該評鑑系統評選結果公布是否在市場上引起異常報酬，並以公司治理評鑑系統評鑑結果之前百分之五企業為樣本，經實證結果分析，顯示第一屆評鑑結果在事件日之前第四個交易日，第二屆評鑑結果在事件日之前第三個交易日，具有顯著之正向標準化異常報酬（SAR）。整體而言，異常報酬最立即反映股價的事件日前後（-1,+1），均無正向顯著之標準化平均異常報酬，說明了公司治理評鑑的公布在市場上並沒有異常報酬，未與效率市場假說（EMH）一致。 公司治理評鑑系統雖然未能產生正向顯著之異常報酬，但能夠被評鑑為績優的前百分之五企業，已經肯定其在公司治理上的努力與成果，對於市場投資人，在選股上仍具有參考價值。 根據過去文獻顯示，公司治理良善之企業均能提高其管理績效之效能，並降低其代理成本。但「公司治理」與本研究主題「公司治理評鑑系統」兩者之間是具差異性的。影響公司治理的良窳，是很多影響變數所組成，而公司治理評鑑系統，僅是評鑑過去一年企業是否符合公司治理規範的最低標準。未來要提高公司治理評鑑系統的能見度與參考價值，建議評鑑指標應考慮加入公司治理之影響變數。

After Enron scandal (2001), “Corporate Governance” has become a world-wide researching issue. Corporate governance is an instructional and managerial mechanism to enhance operating effectiveness and to oversee the management, thus to protect investors, creditors and other interested parties and meanwhile facilitating corporates’ social responsibility.

Since 2002, Taiwan started promoting the idea of corporate governance. However, the scandals revealed in 2003, 2004 and 2007 shows that there still are improvements needed. Recently the polluted water leaking of ASE company, Kaohsiung gas explosions and food safety issues suggested that the importance of corporate governance.

To accelerate the improvement in corporate governance and keep up with other Asian countries, Financial Supervisory Commission (FSC) launched the "Corporate Governance Roadmap 2013". One of the key measure in the roadmap is to establish the evaluation system.

The corporate governance evaluation system held by FSC in 2014 and 2015 had completed. This case study is to test the correlation between corporate governance evaluation and market valuation with event study based on the results ranked in the top 5 percent of corporate governance system of 2014 and 2015. The regression outcomes indicate that there are significant positive standardize average abnormal returns on the transaction day four days before the revealing of governance evaluation of 2014; three days before the revealing of governance evaluation of 2015. Actually, the most intense effect of abnormal returns always impacts on the event case before the event 1 day and after the event 1 day (-1,+1). Overall, there is no significant positive standardize average abnormal returns around the event, it illustrates the corporate governance evaluation is against the Efficient Markets Hypothesis (EMH).

Although corporate governance evaluation does not have positive significant abnormal average returns, being ranked in the top five percent in the evaluation system is still a valuable reference for investors and firmly recognition for the companies.

There are studies indicate that with well-established corporate governance, companies can enhance the effectiveness of management performance and lower agency costs. However, corporate governance evaluation system provides the minimum standard for companies; more factors beyond the evaluation system affect the performance of managements. Therefore the corporate governance evaluation systems cannot represent the influence of corporate governance itself.