What Brings You to the Party? Voter Preferences on Parties Through Policy and Valence Dynamics

Recent studies of party politics suggest that non-policy attributes, or valence, of political parties play a critical role in voter decision-making. However, no research to date has established exactly what types of valence matter and how they interact with parties' policy platforms. This study therefore conducted a conjoint experiment in Japan and find that voters care more about party valence attributes with respect to presence, power, and legislative productivity, as well as the prevalence of scandals, compared to the level of continuity and experience. This pattern persists regardless of electoral system and partisanship. The results also imply that valence is not a substitute for policy and that the effects of valence and policy behave additively. These findings paint a picture of electoral competition centered on both a party's policy offerings and its ability to meaningfully engage in the legislature rather than its continuing existence or the prevalence of incumbent members.