Pregnancy or Motherhood Cost? A Comparison of the Child Penalty of Adopting and Biological Parents

Using Danish administrative data from 1987-2018, I compare the labor earnings trajectories between adopting and biological parents. Adopting mothers by definition do not experience sex-specific comparative advantage in childcare due to pregnancy and nursing. Comparing adopting and biological parents will therefore elicit how much pregnancy to non-pregnancy related factors determine the observed gender inequality in the child penalty. I find large and significant child penalty for all mothers, although slightly smaller for the adopting mothers than for the biological mothers. Neither adopting nor biological fathers experience any child penalties. The results prove that the child penalty is a female burden no matter whether the women carry the biological costs related to pregnancies