Strategic Choices: How Tailored Information Influences Election Dynamics

Political scientists have long been puzzling over why some voters choose parties that they acknowledge as not being the most proximate to their views. This research delves deeper into the determinants of tactical voting by attempting to answer the following questions: How do personal and systemic characteristics shape the impact of personalised political information on tactical voting? In the context of one of Spain's most fragmented and intense general elections on July 23, 2023, we explored these questions. Our study employs data from the largest Voter Advice Application (VAA) in Spain, which attracted nearly half a million users. This digital tool was combined with an innovative survey experiment - the largest online experiment of its kind. We analysed the results of presenting users with their levels of political congruence with different national and regional parties, both before and after assessing their voting probabilities. We discovered a pronounced reinforcement effect among voters of Sumar and Vox when exposed to congruence information prior to voting decisions, while the influence was more subdued for PP and PSOE supporters. Interestingly, however, district magnitude and the voters' level of congruence with their intended party did not significantly affect this trend. Our findings delineate the distinctive impact of personalised political information in a fragmented electoral context and confirm important assumptions in political science that have been open for years: personalised information reinforces but does not convert pre-existing electoral intentions.