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This is an interesting question. As a technical analyst, I believe that company announcements generally come after, rather than before price movements. That is why we use charts.

I am not aware of any work done on this, but there has been some work on the effect of news generally. It is discussed in Irrational Exuberance by Robert Shiller, a book everyone should read.

PS. A reader of my site has brought the book Ahead of the Market - The Zacks Method of Spotting Stocks Early - In any Economy by Mitch Zacks. I have not read it but the reader recommended it to me.