In May 2001, Senator James Jeffords left the Republican Party and tipped control of the U.S. Senate to the Democrats. This paper uses the surprise event to demonstrate what I term the "Jeffords effect": changes in the political landscape have large effects on the market value of firms. I use a...

We show that stock prices underreact when there is a political event, reflected in higher momentum returns. We conjecture that political news crowds out stock news cause investors to distract, trade more indexes and underreact to firm specific news. We analyze momentum returns following general...