Why do parties participate in referendum campaigns? Evidence from Switzerland

This study examines how political parties engage strategically with referendum campaigns, a less-explored aspect of their broader referendum involvement. Building on referendum instrumentalization studies as well as cognate literatures, an analytical framework identifies five potential strategic factors that might explain why parties participate in referendum campaigns and formulates corresponding hypotheses regarding their effect. The framework is applied to 33 recent Swiss referendums, using social media and newspaper advertisements as a proxy for party participation. Binomial logistic regression reveals that public attention for a referendum, its issue’s salience to a party, and (to a lesser extent) a party’s initiator status significantly favor the likelihood of campaign participation, suggesting that Swiss parties primarily leverage referendum campaigns for policy-seeking and image-building strategies. This study therefore contributes to understanding of the interplay between referendums and party strategies in contemporary political contexts, and allows for the expansion of instrumentalization perspectives to include non-initiating parties.