- 學位論文
資訊透明度對股價的影響- 以第五屆資訊揭露評鑑之電子業為例
An Empirical Study of the Impact of Information Transparency on the Stock Price-From the Fifth Information Disclosure and Transparency Raking System on Electrical Industry
摘要
台灣證券交易所(證交所)及財團法人證券櫃檯買賣中心委請證券暨期貨市場發展基金會(證基會)規劃並執行「資訊揭露評鑑系統」，期望藉由獨立、公正、專業、客觀系統化的評量，提高企業的資訊透明度，降低資訊不對稱，強化投資人對資本市場的信心。本研究以第五屆資揭露評鑑之上市櫃電子業做為研究對象，採事件研究法(Event Study)中的市場模式(Market Model)以標準化後之平均異常報酬率（SAR）與累計平均異常報酬率（SCAR) 檢定資訊揭露評鑑結果是否具有資訊內涵。另一目的是以Tobin’s Q 作為公司價值的替代變數，探討資訊透明度較高之公司，市場價值是否較大。 本實證研究發現資訊揭露評鑑評等較佳之上市電子公司，其異常報酬在評鑑等級公佈當日上市電子公司會有正的異常報酬，但未達顯著水準。在上櫃電子公司評鑑等級較佳的公司則明顯高於評鑑等級較差之公司，且達顯著水準，顯示資訊揭露評鑑系統具有資訊內涵。 此外，本研究亦發現以Tobin’s Q 作為公司價值的替代變數，當公司資訊透明度較高時，可減少與投資大眾間的資訊不對稱，獲得投資人的認同，因此公司的價值也相對提升。
並列摘要
“Information Disclosure and Transparency Raking System” was conducted by Securities & Futures Institute, entrusted by Taiwan Stock Exchange and GreTai Securities Market. Evaluation criteria were developed by an independent, fair, professional, and objective organization to promote corporate transparency, reduce the information asymmetry, and strengthen investors’ confidence on capital market. This study tried to explore the impact of information transparency on the stock price-evidence from Electrical Industry of 2007 Information Transparency and Disclosure Ranking Results in Taiwan. The study adopted the market model of event study, using the standardized SAR and SCAR to examine if the result of information transparency and disclosure evaluation possesses the information connotation. Another objective was using Tobin’s Q as the variable parameter of company value, and discussing if the market value was higher concerning company as disclosure level increase. This empirical study found that electrical companies with better information transparency and disclosure ranking results on the market have a positive SAR at the day the ranking result was announced, but it was not significant. It was significant that electrical companies with better ranking result were clearly higher than those with poorer ranking, which showed that the “Information Transparency and Disclosure System” possessed the information connotation. Besides, the study also found that when using Tobin’s Q as the variable parameter of company value, while company has higher information transparency, it can reduce the information asymmetry with the investing public, to enable investors to better protect their interest through us of ranking results as am additional decision-making tool.