The average number of days with sick leave benefits per year is significantly higher among women than among men, and the difference is greatest at the ages when many have small children at home. Women's sick leave increases sharply when they become parents, but the underlying causes are still unclear. Our project investigates two possible explanations for mothers' sick leave: 1) having undergone pregnancy and childbirth, and 2) gender norms that put the main responsibility for house work and childcare on women.

We compare families that have either adopted or biological children, where the parents have the same or different gender, in Swedish and Norwegian administrative data. Through comparisons between families, we will get closer to finding out whether mothers' higher sick leave usage can be explained by the fact that the mother 1) gave birth to the child, or 2) that she is in a relationship where the division of labor is likely influenced more by traditional gender norms.

In order for parents in different family constellations to be more comparable, we use so-called matching methods. If the difference in sick leave usage is large between women who have given birth and who have not given birth, it indicates that measures such as better prenatal care and the opportunity for recovery after pregnancy would be most effective in reducing mothers' sickness absence. If the difference is greatest depending on the mother's partner's gender, it indicates that more equality oriented gender norms and an even division of labor in the home are most important.