Models of electoral competition often follow Downs (1957) and allow candidates to freely adjust their positions in the issue space to capture the majority of voters. The result, in a two-candidate election with a single dimensional policy space and single peaked preferences, is both candidates adopting the position of the median voter. Such convergence is rarely observed and is potentially at odds with the party polarization cited by the media and academics (e.g. Poole and Rosenthal (1991)).
A possible source of the non-convergence of positions is candidate reputation (see, for example, Bernhardt and Ingberman (1985), Enelow and Munger (1993), and Kartik and McAfee (2007)). That is, candidates may find it costly to change positions in the issue space because it affects the voters perceptions of the candidates credibility or character. Indeed, recent presidential hopefuls John Kerry and Mitt Romney can attest to the electoral costs of changing positions to attract voters.
The following study analyzes the nature of the electoral costs senators face when adjusting their ideological position. Using over 50 years of roll call voting scores from the United States Senate, I estimate the structural parameters of a dynamic model of candidate positioning. Using a simulated method of moments (SMM) methodology, I identify the nature of ideological adjustment costs in the U.S. Senate.
Understanding the electoral cost associated with a candidates change in position is important for a number of reasons. First, by finding large costs to adjusting position, one calls into question the empirical validity of the median voter model and the policy predictions based upon it. Second, knowing the nature of these costs is important for understanding the role of candidate credibility and reputation in electoral outcomes. For example, if a large part of the costs senators face are fixed costs, we would expect to see “flip-flopping” senators.
That is, senators who hold a position for long periods of time and make relatively large changes in position when they do change. On the other hand, if the costs senators face are quadratic, we would expect to see “wishy-washy” senators. These senators would change position more often, but with only small moves. Knowing the nature of the costs to changing position is important for predicting electoral equilibria and will shed light on which theoretical models of electoral competition are most appealing on empirical grounds.
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Flip-Flopping: Ideological Adjustment Costs in the United States Senate
