Publish or Procreate: The Effect of Motherhood on Academic Performance

Women are underrepresented in science and representation deficits are even greater for more senior positions and in STEM fields. The dominant explanation is that male and female scientists, even within the same field, publish at unequal rates. Prior studies on select fields suggest that the gender gap in academic productivity reflects differential effects of childbearing on men and women, as women face tensions between the two greedy institutions of family and academia. We study the full population of STEM academics in Denmark and investigate parenthood penalties on scientific productivity of mothers and fathers, who are active in research after the birth of their first child. We employ an event-study approach on annual research publications, an outcome especially relevant in the science domain, and rely on a unique combination of Danish registers and granular bibliometric data on publications from the database Scopus. We find that, on average, the first childbirth results in an annual penalty of 24 percent on scientific productivity of mothers in STEM fields relative to fathers in the first 5 years after birth. This reflects a drop in annual research publications of mothers relative to their own pre-birth productivity. Hence, unequal impacts of parenthood may be an important driver of gender inequality in science.