Multigenerational effects of smallpox vaccination

This paper aims at finding whether vaccination in childhood is an important source of improved health over the life cycle and across generations. We leverage high-quality individual-level data from Sweden covering the full life spans of three generations between 1790 and 2016 and a historical quasi-experiment – a smallpox vaccination campaign. To derive the causal impact of this campaign, we employ the instrumental-variables approach and the siblings/cousins fixed effects. Our results show that the vaccine injection by age 2 improved longevity of the first generation by 14 years and made them much wealthier in adult ages. These effects, with the magnitude reduced by two thirds, persisted to the second and the third generation. Such magnitudes make vaccination a powerful health input in the very long term and suggest the transmission of environmental beyond genetic factors.