Your Season of Birth Tells much of you and your Background European Edition

ABSTRACT I adapt the approach in Buckles and Hungerman (2013) to show that in several European Union (EU) countries, between 2004 and 2020, the characteristics of the mothers giving birth in different quarters are significantly different. An implication of this finding is that quarter of birth is not a valid instrument in several applications where it has been used, e.g. return to education, even within the EU context. Beyond standard methods, partial identification techniques may help address this limitation.