The political legacy of disease control: Evidence from a polio vaccination campaign in China

Although recent studies have explored the long-term effects of disease control on individuals' educational and labor market outcomes, much less is known about its political consequences. This paper uses the polio vaccination campaign in China as a successful historical event to analyze how disease control interventions affect political trust in adulthood. By combining province-level variation in prevaccine incidence with cohort-level variation in trust-formation ages, we construct individual exposure to the vaccination campaign using a difference-in- differences strategy. Our findings show that exposure to the polio vaccination campaign during the trust-formation period positively affects trust in local government over four decades later. Mechanism analysis highlights that internal belief formation and updates are crucial for these long-term impacts. Further evidence indicates that this trust-building effect is specific to political institutions and public health sectors. Our findings indicate the importance of understanding historical disease control interventions for state legitimacy.