Age, motherhood and the gender pay gap

That’s a justifiable thing to say if you look at millennials.

Jo Swinson based her claim on analysis by the Resolution Foundation think tank. It looked at survey data from the Office for National Statistics and found that middle-earning women born between 1981 and 2000 earned around 5% per hour less than their male counterparts, a smaller gap than in previous generations.

In other words, if you knew absolutely nothing else about two workers in the UK, aside from the fact that one was a woman, one was a man, and both were in their twenties, on average you would expect the woman to earn roughly 5% less per hour than the man.

The claim also happens to be justified if you look at the middle-earning woman each week aged 22-29. She earned around 6% less each week than the middle-earning man last year.

Gender pay gap stats are useful, but have their limitations

Although there is a gap between the pay of men and women, it’s harder to say what the statistic tells us.

As the Resolution Foundation pointed out, its measure of the ‘gender pay gap’ isn’t comparing like-with-like. It’s comparing median average earnings in the whole group of women who work, against the whole group of men who work.

That’s a bit different from what people often think of as the ‘gender pay gap’: the idea that a woman will be paid less than a man for doing exactly the same job.

For one reason or another, men and women in the UK tend towards different kinds of jobs, tend to work different hours, and arguably develop different skills and experience.

So there are a range of additional reasons why the gender pay gap might exist, alongside the possibility of outright discrimination.

Although gendered wage inequalities suggest a lot about the way we organise and value different kinds of work across society as a whole, and particularly how these kinds of social pressures and choices are gendered, they aren’t a direct measure of discrimination in the workplace.

And there’s more than one reasonable way to measure them. The ONS suggests looking at full-time workers alone is a good headline measure. But the Resolution Foundation told us that it chose to include part-time workers this time, since it thinks the gap in hourly pay between full-time and part-time work is an important issue.

As the ONS has put it:

Different measures of the gender pay gap will capture different aspects of how the UK labour market is shaped by gender.

Many people cite motherhood as one key reason for the gap

On the one hand, there’s evidence that the gender pay gap increases later in life, partly as women become mothers.

A recent report by the IFS think tank chose a third measure of the gap to both the Resolution Foundation and the ONS, which helped illustrate a different point: it showed that although a gap in mean average pay for men and women exists before people become parents, the gap increases steadily and substantially for 12 years after the birth of their first child.

The IFS’ main interpretation is that mothers who choose to take time out of work miss out on workplace skills and experience, and so lose the opportunity for career progression.

As with other statistics on gendered pay inequalities, there’s room for a range of interpretations.

On the other hand, we haven’t seen clear evidence yet that the same women are getting ahead of men in terms of pay before they have children. The IFS found that over a third of the eventual difference in average wages between mothers and fathers existed before the first child was born.

Jill Kirby pointed us to a Guardian article from 2015, which was based on data collected by the Press Association. This suggested that women in their twenties were earning more than men. It’s not clear exactly how these figures were put together, or whether the analysis is still up-to-date, so we’ve asked the Press Association for the original release.

Back in 2015, it was true that women aged 22-29 working full-time earned more each hour than their male counterparts. That was no longer the case in 2016.