What ends justify the means? Explaining party spending intensity in referendum campaigns in Europe

Abstract This study investigates expenditure of European parties in referendum campaigns. Previous work exploring why parties initiate referendums hints at the importance of subsequent campaigns to parties, but theoretical insights regarding party behavior in campaigning contexts are fragmented and limited. We argue that party expenditure indicates the extent of their engagement, and identifying explanatory factors can offer insights into underlying strategic goals driving parties in their behavior. Drawing on referendum instrumentalization literature and existing empirical studies, we propose a framework with three strategic factors and corresponding hypotheses. These are tested using official expenditure data for 47 parties campaigning in 24 referendums in eight European countries through bivariate and multivariate analysis. Our findings mainly suggest that parties see referendum campaigns as avenues for image building, spending more on average when they initiate them and when referendums are publicly salient. Additionally, parties seemingly prioritize elections, while spending limits are ineffective in curbing expenditure.