Party brands, issue salience, and electoral volatility
研究政党在议题强调上的相似性如何影响选举波动性，发现当政党议题策略趋同时，选民更易转换投票对象，且这种效应在政党立场相近时更强。
Rates of vote switching and electoral volatility have risen across Europe. The degree of programmatic differentiation between parties is a crucial determinant of volatility. When parties take similar positions, thereby diluting their brands, citizens are less likely to keep voting for the same party. However, we have yet to systematically consider the role of party distinction in terms of issue emphasis. Does volatility increase when parties dilute their brands’ issue salience component? I use issue salience divergence in party manifestos matched with national election results and cross-national election survey data to capture how issue salience structures aggregate electoral volatility and voter flows between parties in Western Europe. I find that elections are more volatile when parties emphasize issues more similarly, though this result is sensitive to model specification in aggregate analyses. At the dyadic-level, I find robust evidence for a substitution effect. Issue salience divergence matters more when party positions are similar and vice versa. Because most vote switching occurs between proximate parties, these results reinforce the importance of considering issue salience divergence alongside positional distinction. These findings contribute to growing fields on the increasing volatility of politics in Europe and the variety of ways parties build and dilute their brands.