Replication Data for: Do Effortful Apologies Matter in International Historical Disputes? Experimental Evidence from South Korea

Political apologies have become an important tool for addressing historical injustices, yet their effectiveness—especially in international contexts—remains debated. Prior scholarship has highlighted the limitations of simple verbal apologies and emphasized the importance of tangible and observable measures. What remains unclear, however, is why such measures enhance sincerity. I argue that their effectiveness hinges on the extent to which they are perceived as requiring effort in crafting and delivering apologies. This study examines whether—and if so, how—perceived effort shapes evaluations of sincerity, drawing on two pre-registered survey experiments in South Korea that used the same survey instrument and vignette treatments, in which respondents evaluated apologies issued by Japan for its colonial rule. The results demonstrate that apologies accompanied by concrete reparative measures are perceived as involving greater effort, which in turn elevates both credibility and sincerity. These findings underscore the importance of designing political apologies that are both symbolically meaningful and visibly effortful in international historical disputes.