Somchai_Stock/ShutterstockDespite decades of progress, the gender pay gap remains a persistent feature of the UK labour market. According to women’s rights charity the Fawcett Society, November 22 marked Equal Pay Day 2025 – the day when women effectively stop getting paid due to the wage gap with men.
This gender pay gap means women continue to earn less than men – currently by around 11% in the UK. This is not just because of differences in education or job type, but due to deeper inequalities in how work and care responsibilities are distributed.
A study on barriers to equal pay that I undertook with colleagues used 40 years of work history data from the UK Household Longitudinal Study to uncover how these inequalities play out across income groups.
We found that differences in work history – particularly full-time employment – account for nearly 29% of the gender pay gap on average. Women have shorter full-time work histories and spend more time doing part-time roles and unpaid care work. This reflects the challenges of reconciling paid employment with caregiving responsibilities.
For example, men in our sample had an average of 20 years of full-time work, compared to 14 years for women. Women also spent significantly more time in unpaid family care – more than two years on average – while men had less than three weeks.
This disparity is not just about time, it’s about how the labour market rewards different types of work. Full-time work earns a premium, while part-time work and unpaid care are penalised. Our research found that a year of full-time work increases hourly pay by 4%, while a year of part-time work decreases it by 3%.
The cost of being female
Even after education, occupation, sector and work history are taken into account, women still face a significant pay penalty. We found that this “female residual” – a proxy for discriminatory pay practices and cultural biases in how women and men behave – accounts for 43% of the average gender pay gap. This is an astonishing finding from a complex model that controlled for a wide variety of predictors of pay differentials.
In low-income households, the penalty is even more severe. Women in these households would earn more than men if not for this “female residual”. For example, for low-paid public sector workers, other factors like education and work history might create an expectation of women outearning men. But the female residual here meant that any advantage was cancelled out.
This finding challenges the assumption that discrimination is more prevalent among high earners and underscores the need to focus on inequality at the bottom of the income distribution.
Interestingly, the impact of part-time work varies by income group. Among wealthier households, part-time work increases the gender pay gap. But in poorer households, it does not appear to carry the same penalty – and may even offer a slight premium for women. This suggests that exposure to part-time work for men in lower income groups is associated with very low pay.
With this in mind, policies encouraging full-time work for women may not be appropriate for all groups. In low-income households, part-time work may be a necessary and viable option, especially when the quality of the available jobs is poor and caregiving responsibilities are high.
However, we also found that men face a stronger penalty for part-time work than women, which may discourage them from sharing caregiving duties. This reinforces traditional gender roles and perpetuates inequality.
Sex-segregated occupations – those dominated by either men or women – also play a role in the gender pay gap. Female-dominated jobs (for example, care work, hospitality and retail) tend to be lower paid, less regulated and offer fewer opportunities for progressing up the career ladder.
We found that this segregation accounts for 17% of the average gender pay gap. Yet, we also found penalties associated with male-dominated occupations such as construction, particularly in low-income households. This challenges the assumption that male-dominated jobs are always better paid.
On the other hand, we found that public-sector employment, union membership and paid parental leave reduce the gender pay gap, especially for women in low-income households. These offer some protection against discrimination at the same time as supporting work-life balance.
But these benefits are not evenly distributed. Women in wealthier households are less likely to rely on these protections, while those in poorer households benefit disproportionately. This highlights the importance of jobs that offer these protections for low-income workers.
Our findings suggest that equal pay policies must be tailored to the needs of different income groups. For wealthier households, policies that support full-time work and chip away at sex segregation may be effective so that women can more readily access better-paid jobs.
But for poorer households, the focus should be on improving access to stable and better-paid jobs, while reducing discrimination and supporting flexible work arrangements.
Crucially, efforts to close the gender pay gap must avoid pitting the gains of high-earning women against the losses of low-earning men. In an era of rising political populism, this could undermine support for equality.
Instead, we need an approach that promotes good-quality employment for all and that supports equalised caregiving responsibilities. If we fail to address the barriers that prevent men and women from participating fully in both paid work and unpaid care work, we are unlikely to see reductions in the gender pay gap any time soon.
Vanessa Gash does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.