Online Appendix: Using Moral Foundations in Government Communication to Reduce Vaccine Hesitancy

This is the online appendix for the article Using Moral Foundations in Government Communication to Reduce Vaccine Hesitancy. Using vaccination information brochures from the Dutch National Institute for Public Health and the Environment (RIVM) we analyse the use of Moral Foundations in this context of government communication. We find that RIVM predominantly uses the dimensions of Harm/Care and Purity/Degradation in its communication with parents. By contrast, the dimensions Authority/Subversion and Fairness/Cheating play only a minor role or no role in government communication with parents. We employ these results to investigate the effect of this communication channel on vaccination rates. While prior research has shown that vaccine hesitant individuals emphasise the Moral Foundations Liberty/Oppression and Purity/Degradation, our results confirm this relationship only with respect to the dimension Liberty/Oppression. For the use of Purity/Degradation, by contrast, we find no significant effect on parents' vaccine hesitancy. Instead, Authority/Subversion appears to reduce, while Loyalty/Betrayal increases vaccine hesitancy.