Trading on Private Information: Evidence from Members of Congress
研究发现2004-2010年间，有权势的共和党议员股票投资组合异常回报率超过35%，但2012年《禁止利用国会知识交易法案》通过后，这种异常回报消失，表明该法案抑制了议员利用私人信息交易的行为。
Abstract I examine the stock trades of members of Congress and find that over 2004–2010 the buy‐minus‐sell portfolios of powerful Republicans have the highest abnormal returns, exceeding 35% on an annual basis under a one‐week holding period. Among powerful Republicans, the abnormal returns are mostly concentrated in the portfolios of those with less trading experience. I also find that the positive abnormal returns disappear after the Stop Trading on Congressional Knowledge (STOCK) Act was passed in 2012. My results imply that the STOCK Act affected politicians' incentives to trade on private information, which they acquired through their power and party membership.