Insider Trading Laws and Stock Price Informativeness
利用48个国家1980-2003年的数据，发现首次执行内幕交易法能提高股价信息含量，但仅限发达市场；在新兴市场，由于内幕人士的信息注入作用消失，效果不显著。
We investigate the relation between a country's first-time enforcement of insider trading laws and stock price informativeness using data from 48 countries over 1980--2003. Enforcement of insider trading laws improves price informativeness, as measured by firm-specific stock return variation, but this increase is concentrated in developed markets. In emerging market countries, price informativeness changes insignificantly after the enforcement, as the important contribution of insiders in impounding information into stock prices largely disappears. The enforcement does not achieve the goal of improving price informativeness in countries with poor legal institutions. It does turn some private information into public information, thereby reducing the cost of equity in emerging markets. The Author 2008. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.