Replication Data for: “Reassessing the Electoral Effects of Party-Leader Visits in Parliamentary Democracies: Evidence from Japan”

Leader-centered campaigning is increasingly central to parliamentary elections, but published evidence on the effects of party-leader visits remains scarce. Prior studies typically rely on lagged outcomes as proxies for pre-visit competitiveness, a strategy vulnerable to bias when constituency dynamics shift between contests. This article analyzes Japan’s House of Representatives elections from 2014 to 2024 using an alternative approach: qualitative constituency-level assessments from six major media outlets, aggregated through an item response theory (IRT) model to generate contemporaneous measures of competitiveness. Across more than 500 constituency-election observations, OLS and Matching consistently show that prime ministerial visits had negligible effects on governing-party candidates’ vote-share margins, even in competitive races. Further analysis shows that party leaders in fact targeted constituencies that had become more competitive since the previous election, leading reliance on lagged outcomes to misstate visit effects. The findings suggest limited local influence of leader-centered campaigning in parliamentary systems and contribute methodologically by offering an alternative framework for evaluating campaign situations more credibly.