資訊透明度與公司股價報酬變異-以證基會資訊揭露評鑑系統為例

Abstract

公司治理為企業追求永續發展中最重要的手段之一，良好的公司治理制度不僅可使得公司能夠有效運作，亦有助於提高投資人之信心。2004年OECD（經濟合作開發組織，The Organization for Economic Cooperation and Development）提出的公司治理原則當中提到：公司治理架構應確保即時且正確地揭露任何攸關公司的重大資訊，包括財務狀況、經營績效、股權概況及公司治理等，想見公司資訊揭露實為公司治理一大重要關鍵，亦可說是公司永續經營的首要工作。 近年來台灣證券管理機構更積極藉由法規的修訂來改善企業的資訊揭露及透明度，本研究以證券暨期貨市場發展基金會於2004年起建立之資訊揭露評鑑系統其評鑑結果為基礎，探討當公司之資訊透明程度變動時是否會對該公司之股價報酬變異有顯著影響。本研究中各個模型設計皆採用二階段最小平方法作為統計分析方法。本篇末段由迴歸分析結果可歸納出一重要結論：當資訊透明程度提高，將使得公司股價報酬變異相對穩定，進一步使得公司涉險程度降低；而此結論提供充分證據支持公司可藉由提高資訊透明度之政策來降低公司涉險程度。

Corporate governance is one of the essential means for a firm to survive volatile business environments. Integrated corporate governance framework makes companies operate more effectively and earns stakeholders’ trust. OECD (Organization for Economic Cooperation and Development) stated that an important quality of corporate governance is disclosure. A firm should disclose any major information accurately and timely, including financial status, firm performance and corporate governance; this statement illustrates the importance of information disclosure in corporate governance. In recent years, authorities revised financial regulatory framework to improve disclosure and transparency mandates. The paper discusses the association between the variance of information transparency and the variance of stock return. We estimate the variance of information transparency by using the Information Disclosure and Transparency Ranking System (IDTRS) which is a database developed by the Securities and Futures Institute and released every year since 2004. In order to reduce the endogenous problem, we construct models by two-stage least squares method. Collectively, our results provide empirical evidence suggesting that the greater transparency of information, the less risk will be taken by company.