Partisan dividends: The policy impact of partisan turnover

Theories of congressional organization continue to be at odds over the value of majority party status in the legislative process. There are a number of ways in which majority status is thought to be valuable, and thus a number of ways one might try to detect party effects in congress. My dissertation exploits instances of change in majority party control of one or both chambers of Congress, and the presidency, to capture the policy value of majority party status. Unlike conventional studies of public policy, however, I use an "event study" research design (often employed in finance and economics, but rarely in political science) to capture the immediate reactions of attentive, well-informed market investors to these changes. By capturing the expected policy impact, I avoid the threats to validity (and thus causal inference) that are often associated with the long time-horizons of policy studies. My dissertation consists of three papers, which apply this methodology to three instances of partisan turnover: the Jeffords switch in the Senate in 2001, the Presidential election of 2000, and the midterm election of 1994. In all three cases, the evidence points to a simple conclusion: parties matter.