中文摘要：

本文将公司披露整体水平与披露要素纳入信息披露机制的同一框架,考察其对信息泄露及股价操纵的作用,实证分析中国上市公司2001-2013年的信息披露实践及其对投资者保护的有效性。研究发现,上市公司信息披露整体质量逐年改善,但盈余管理程度仍然严重,年报披露的滞后现象未得到实质改善;公司披露质量分别与信息泄露程度、超额收益波动率负相关,它对投资者保护的效用至少存在截面差异,且在向下盈余管理的公司中尤为显著;信息披露质量差的公司超额换手率也高,＂跟风＂特征明显;披露要素的效用各有不同,可靠性对抑制股价被操纵的作用更显著,及时性在抑制＂跟风＂上更有效。促进我国上市公司提高信息披露质量可以改善对投资者的保护效用。

英文摘要：

This paper incorporates disclosure overall level and its components into one mechanism framework,empirically analyzes the disclosure practices of Chinese listed companies from 2001 to2013 and their investor protection efficacy through investigating their restraints on information leakage and price manipulation. The results show, though disclosure overall quality has improvement year over year,serious earning management and annual report disclosure delay are not fundamentally improved; The disclosure quality has significantly negative correlation with information leakage level and stock abnormal return volatility respectively,especially for downward earning management companies; The serious ＂following- the- wind ＂ feature leads to higher abnormal turnover rate for worse disclosure quality companies; Disclosure elements have different effects on investor protection. Reliability performs better on stock price manipulation restraint whereas timeliness is more effective on ＂following- the- window ＂ suppression. Therefore,promotion to improve the disclosure quality can improve investor protection in China.