In the article on couples and capital, we saw that the partner who earns less loses more in a separation. That leaves the question people ask us right away, and it's a fair one: who decided that this partner would earn less? If she paused her career for the children, she must have wanted to. Let's play devil's advocate and see what holds up.
What the numbers measure
In France, Insee surveyed parents of children under eight in 2010. More than one mother in two (55%) stopped working or cut her working time for at least a month beyond maternity leave; among fathers, 12% did so beyond paternity leave. Breaks are more common as the family grows: 28% of mothers stop for a first child, 55% from the third.
Later, salaries follow. An Insee study of the private sector (2005-2015) compares each parent with what would have happened without the child. Five years after the birth, mothers had lost about 25% of their employment income; fathers had lost almost nothing. Most of it comes from activity itself (breaks, part-time work); the hourly wage also falls by about 5% per child on top of that.
In Denmark, where the data span more than thirty years, mothers' income levels off ten years after a first child at about 20% below its earlier level, while fathers' income doesn't move. According to the authors, the share of the gender income gap that is due to children rose from about 40% in 1980 to about 80% in 2013.
Where the devil's advocate has a point
And in part, he's right. Nobody forces a mother to take parental leave, and many say they do it because they want to. Among mothers who took full-time parental leave, about 90% cite "the best solution for the child" and 89% "the wish to devote themselves to their upbringing". In four cases out of five, the decision was made before the birth. So part of the gap really is a choice, in the sense that the people involved describe it that way.
But let's look at what these same mothers also say. A third (33%) answer that another form of childcare would have been too expensive, 17% that there was no other option nearby, 17% that their working hours didn't fit with childcare hours. The reasons add up: the survey allowed several answers. And these are stated reasons, not an experiment in which the price of childcare was changed to see whether the decision changed.
Three ways to read the same fact
As obligation, or rather as arithmetic. The Insee study separates two explanations precisely: preferences and norms, or financial incentives. Result: the losses are very unequal depending on the earlier salary. For the 5% of lowest-paid women, employment income is 38% lower five years after a first child; for those who earned the most, the loss is almost negligible. The authors conclude that households seem to adjust to incentives: when the salary is low, the cost of childcare weighs more than what a job brings in, and a flat-rate benefit for cutting back on work is more attractive. Among fathers, 30% of those who didn't take parental leave cite a fear for their job or career, against 16% of mothers; 46% say they weren't interested at first, against 25% of mothers. The household's arithmetic is rational; it just doesn't cost the same to the one who slows down.
As choice. Some people prefer time with their children to a career, and that is respectable. The point to look at is whether the choice was made knowing what it will cost later: at separation, at retirement, at the other's death. The surveys don't measure what people knew at the time of deciding, so we don't know whether that cost was known.
As repetition. The Danish data don't point to a simple specialization calculation: women whose education level is high compared with their partner's suffer about the same penalty as the others. The authors link the daughters' penalty instead to how roles were split between their maternal grandparents: when the grandmother worked very little compared with the grandfather, her granddaughter suffers a larger penalty. Nothing of the kind shows up on the paternal grandparents' side. That is consistent with the idea that preferences form in childhood, from the roles we see around us. A US study of couples' incomes (censuses from 1970 to 2010) finds, for its part, a sharp drop in the number of couples where the wife earns more than the husband, just past 50% of household income. The authors attribute it to gender norms: when the wife earns more, she does on average a larger share of the housework, and couples are more often dissatisfied and more often divorced.
The same fact, a slowed-down career, can therefore come from all three at once. None of the studies cited here can say in what proportion. What matters for public action, as the Insee authors point out: if norms dominate, extending paternity leave helps; if costs dominate, lowering the price of childcare helps more. A Norwegian study they cite suggests that developing early-childhood services is more effective than extending paternity leave.
Why this changes how we read the previous article
Slowing down your career for the family is an investment that only pays off if the couple lasts: the loss of salary and pension rights is certain, the benefit depends on the other person. As we read it, it is the same mechanism as rent paid for nothing in return, seen from the career side: you invest in a relationship, and get nothing back if it ends.
Hence the underlying question, the one about how we think of a couple. Are we a team, whose capital and careers are shared property, or two individuals who pool resources and leave with what is in their own name? Neither answer is wrong. What costs a lot is living in one while believing you're in the other.
The questions, not the answers
- Who slows down when a child arrives, and who decided? Did we look at other options, including the real cost of childcare?
- How much does it cost the one who slows down, in salary, pension and capital? And who makes up for that cost if the couple separates?
- Would we have made the same choice if the roles were reversed?
- What did we see our parents do, and did we ever question it?
We have no answer to give in your place. But when someone tells you "it was her choice", the right reply may be to ask: under what conditions?
Written on October 28, 2026