The transfers game: A comparative analysis of the mechanical effect of lower preference votes in STV systems

Abstract

Debates about electoral reform revolve around giving voters more choice. Consequently, reformers often favor adopting the single transferable vote, a candidate-based system that allows voters to rank order candidates. Nonetheless, studies about whether lower preferences (transfers) influence STV election outcomes remain scant. To address this gap, our comparative multivariate approach tests transfers' impact on election results in Ireland, Malta, Northern Ireland, and Scotland. We find that, on average, transfers are pivotal in the election of about one in 10 elected candidates. Hence, their impact is the exception rather than the norm. We show that when lower preferences are decisive at the candidate level, they benefit smaller and moderate parties and non-incumbents and, in Malta and Ireland, female candidates. Our results have implications for understanding the extent to which multiple preferences influence election outcomes and for debates on electoral reform.