THE PROBLEM OF PARTY CONVERGENCE JANE GREEN Hallsworth Research Fellow School of Social Sciences University of Manchester
[email protected] Earlier versions of this paper have been presented at the American Political Science Association annual meeting in Chicago, August 2007, the University of California, Berkeley Politics seminar, October 2007, a research colloquium for the College of William and Mary, Virginia, November 2007, and at the University of California at Davis research seminar, December 2007. I wish to thank James Adams, Laura Stoker, Eric Shickler, Ron Rapoport and Russ Dalton for their valuable comments on this paper. The remaining errors are the full responsibility of the author. The Problem of Party Convergence Political parties are expected to pursue moderate policies to gain votes, and so two parties pursuing the same strategy will eventually converge. I argue, however, that two parties cannot pursue an optimal strategy and share similar policy ground. Using a new measure in the 2005 British Election Study, and introducing the choice of third parties and new dimensions, this paper demonstrates that voter abstention and switching due to indifference can strongly outweigh votes gained by spatial proximity. However, parties experience these effects differently. The findings have implications for how we understand the policy positions of political parties in Britain and beyond. 1 Spatial modellers point to a lack of examples of party convergence to question the expectations of Downs (1957).1 They explain instead why parties tend to take polarised positions relative to their opponents (See Adams 2001; Adams and Merrill 2001; Adams and Merrill 2003; Adams et al.