資訊不對稱可能引導公司利害關係人作出錯誤決策，甚至進而影響經濟秩序。為了瞭解企業資訊揭露對投資人資訊不對稱之影響，本研究以買賣價差、股票週轉率、市場風險以及對稱性綜合指標衡量資訊不對稱程度，以證基會所公布之資訊透明度評鑑結果作為企業資訊揭露程度之衡量。經採用2011至2012年台灣上市公司為樣本進行實證研究，實證結果發現，在控制潛在影響因素下，資訊揭露程度與買賣價差呈負向關係，並與股票週轉率及對稱性綜合指標呈正向關係，顯示公司資訊揭露可降低資本市場資訊不對稱情形。
Information asymmetry would lead stakeholders to make suboptimal decisions and even make a bad impact on economic order. To address the issue of whether corporate disclosures affect information asymmetry among investors, this study uses bid-ask spread, share turnover, market risk and a composite indicator to measure level of information asymmetry, and employs information disclosure and transparency rankings released by SFI as a proxy for extent of disclosure. Using companies listed in the Taiwan Stock Exchange from 2011 to 2012, we find that, after controlling for potential confounding factors, the extent of disclosures is positively associated with share turnover and the composite indicator, and negatively related to the spread var-iable, indicating that more corporate disclosures can mitigate information asymmetry among investors.
