Family size and vaccination among older individuals: The case of COVID-19 vaccine

While vaccination is generally considered efficient in protecting against transmissible diseases, the compliance is not complete in many countries. In this study, we investigate how an individual-specific factor - family size - affects the probability of getting vaccinated against COVID-19. To answer this research question, we focus on individuals above 50 years of age, who are at a higher risk of developing severe symptoms. The analysis uses the Survey of Health, Ageing and Retirement in Europe Corona wave, conducted in the summer of 2021. To identify the effect of family size on vaccination, we exploit an exogenous variation in the probability of having more than two children, due to the sex composition of two firstborns. We document that a larger family size increases the probability of receiving the COVID-19 vaccine among older individuals. This impact is economically and statistically significant. We propose several potential mechanisms behind this result and document that family size can be related to the higher probability of being exposed to the disease. This effect can be by knowing someone who tested positive for COVID-19 or had symptoms similar to it, and by network size and frequency of contact with children, before the outbreak of COVID-19.