Background: After the emergence of the frst vaccines against the COVID-19, public health authorities have promoted mass vaccination in order to achieve herd immunity and reduce the efects of the disease. Vaccination rates have difered between countries, depending on supply (availability of...

We study the effects of maternal age on infant health. Age at birth has been increasing for the past several decades in many countries, and correlations show that health at birth is worse for children born to older mothers. In order to identify causal effects, we exploit school entry cutoffs and...

We study the effects of school starting age on siblings' infant health. In Spain, children born in December start school a year earlier than those born the following January, despite being essentially the same age. We follow a regression discontinuity design to compare the health at birth of the...