“I’m coming back part-time after maternity leave.”

It is a sentence I started hearing repeatedly after moving to the UK. This surprised me because it was not something I had heard nearly as often before.

Of course, there are many reasons why somebody may decide to reduce their hours after having children. Family preferences, cultural norms and personal circumstances all matter. There is absolutely nothing wrong with deciding to spend more time at home with young children if that is what works best for a family.

However, when I signed up my own children for nursery for the first time, I started to understand more clearly why this conversation seemed so common in England.

When childcare costs represent a substantial share of a salary, many families begin to ask difficult questions. Does it make financial sense for both parents to continue working full-time? Would it be better for one parent to reduce their hours? Should someone temporarily leave the labour market until children are older? And in practice, these decisions disproportionately affect women.

Of course, we need to be careful here. This is not proof that every woman who reduces her hours does so because childcare is expensive. But the pattern is difficult to ignore. OECD data shows that net childcare costs remain particularly high in countries such as the UK and New Zealand, even after childcare benefits and tax support are taken into account (OECD, 2024). The Institute for Fiscal Studies has also shown that mothers are much more likely than fathers to move into part-time work after having children, and that this is one reason why the gender pay gap widens over time (IFS, 2016).

At the same time, recent Office for National Statistics analysis for England shows that motherhood has a large and persistent effect on women’s earnings and employment. Five years after the birth of a first child, mothers’ monthly earnings are, on average, 42% lower than in the year before birth, equivalent to £1,051 per month. Across the first five years after a first child, the average total earnings loss is estimated at £65,618 (ONS, 2025). This suggests that childcare costs are not simply a private family expense. They are one of the mechanisms through which having children can affect women’s long-term labour market outcomes.

This is one of the reasons economists talk about the motherhood penalty: the reduction in earnings, career progression and labour market opportunities that many women experience after having children.

And yes, childcare costs are part of this story, but they are not the whole story.

A large body of research, particularly the work of Nobel Prize-winning economist Claudia Goldin, suggests that the motherhood penalty is also related to the way many jobs are organised. In her work on gender gaps in the labour market, Goldin argues that many high-paying jobs reward long hours, constant availability and very limited flexibility. She describes these occupations as involving “greedy work” (Goldin, 2021).

In a number of professions, the highest rewards do not simply come from doing your job well. They come from being available to work extra hours, travel at short notice, attend meetings outside normal working hours, respond to emails in the evening or take on additional responsibilities that were never formally written into the employment contract.

These are the hidden, non-monetary costs of career progression.

Before having children, many workers are able and willing to provide this flexibility. After becoming parents, things become more complicated.

This does not mean that parents become less productive or less talented. However, it may mean they become less able to provide the constant flexibility that some jobs reward disproportionately. Career progression can therefore slow down, and if we add high childcare costs to this equation, the effects can become even stronger.

And while these decisions may be perfectly rational from a family perspective, they often have long-term consequences, what economist call a trade-off.

Time out of the labour market can make it more difficult to return to previous career trajectories. Part-time workers may miss promotions, training opportunities or professional networks. Colleagues who remain continuously in full-time employment continue accumulating experience, skills and visibility within organisations.

The result is that a temporary adjustment made during the early years of a child’s life can have effects that last for decades.

This is why things that can look insignificant for some such as subsidssing early years education is a much bigger national question.

It is about labour market participation.

It is about career progression.

It is about gender inequality.

It is about equality of opportunity.

References

Goldin, C. (2021). Career and Family: Women’s Century-Long Journey toward Equity. Princeton University Press.

Goldin, C. (2014). A Grand Gender Convergence: Its Last Chapter. American Economic Review, 104(4), 1091–1119.

Office for National Statistics (2025). The impact of motherhood on monthly employee earnings and employment status, England.

Farquharson, C., and Olorenshaw, H (2022). The changing cost of childcare. Institute for Fiscal Studies.

Institute for Fiscal Studies (2016). Mothers suffer big long-term pay penalty from part-time working.

OECD (2024). Net Childcare Costs Database.