資訊揭露與透明度為公司治理的重要構面之一，在良好的公司治理下必有透明的資訊，透明的資訊可以減少資訊不對稱，使投資人對公司有信心，減低交易成本而增加公司股票的需求，使權益資金成本得以降低。然而影響權益資金成本的因素並不只有資訊揭露，故本研究加入會計政策選擇以探討會計政策選擇與揭露程度對權益資金成本之影響。
本研究的應變數為權益資金成本，以CAPM估計。對於揭露程度分為兩個面向探討，年報揭露與即時揭露，年報揭露採內容分析法，參考國內外文獻整理出年報揭露評分表對公司年報進行評分；即時揭露以公開資訊觀測站重大訊息公布的資訊衡量。而新加入的會計政策選擇變數係以公司盈餘管理的多寡來定義所適用的會計政策；積極或保守的會計政策，再進一步探討在不同會計政策下，年報中自願性揭露與權益資金成本的關係。
本研究採用最小平方法多元迴歸分析對假說進行測試，樣本為2004年國內資訊電子業121家公司。實證結果顯示，年報資訊揭露程度與權益資金成本並未如預期呈現顯著負相關；即時資訊與權益資金成本呈現顯著正相關；會計政策愈積極，權益資金成本愈高。選擇積極會計政策公司，自願性揭露與權益資金成本呈不顯著負向關係，但選擇保守會計政策公司，自願性揭露愈多會有愈高的權益資金成本。
The information disclosure and transparency is one of the important structure for the corporate governance. Under the well corporate governance condition must have transparent information. Transparent information can reduce information asymmetry and transaction costs and enhance investor’s confidence and demand of stocks, further-more, to decrease enterprise’s cost of equity capital. But information disclosure is not the only one factor to influence cost of equity capital. We add accounting policy choice to our research and discuss the effects of accounting policy choice and disclosure on cost of equity capital.
Our dependent variable is cost of equity capital and we use CAPM to estimate it. In this research we discuss disclosure with two streams : annual disclosures and timely dis-closures. We use content analysis for annual disclosures and refer to past literature to construct our disclosure score table. According to the disclosure score table calculate each company’s disclosure score. We measure timely disclosure as the frequency of company’s announcement on the Market Observation Post System in Taiwan. Consid-ering the new variable, accounting policy choice, we use earning management depth to decide which policy they adopt, aggressive or conservative. Furthermore, we divide the sample into firms making aggressive accounting choices and those making conservative choices to discuss the relationship between voluntary disclosure of annual report and cost of equity capital in different accounting choices.
In this research, we use multiple regression to test our hypothesis. We obtain 121 sample firms from IT industry in 2004. The empirical results show that annual disclo-sures not confirm our prediction. There is no significant negative relationship between annual disclosure and cost of equity capital. But the empirical results of timely disclo-sure and cost of equity capital are the same as our prediction. There is significant posi-tive relationship between timely disclosure and cost of equity capital. And we find that firms adopt aggressive accounting policy have higher cost of equity capital. Finally, we divide the sample into aggressive firms and conservative firms. We find there is no sig-nificant negative relationship between voluntary disclosure of annual report and cost of equity capital in aggressive firms. But there is significant positive relationship between voluntary disclosure of annual report and cost of equity capital in conservative firms.
