Research on socially irresponsible firms and firm value. Looked for articles in major news agencies on companies who have been irresponsible, then looked at their stock price for the seven days leading up to the article and seven days following the article to see if there were statistically any abnormal differences in prices.
Some firms had significant abnormal negative returns, but most didn't. Abnormal negative returns were short lived, meaning their stock prices returned to normal after a short period of time.
Why would that be? can you find some negative articles on companies and tell me if their stock price suffered in the short run and long run?