A report by the Institute of Fiscal Studies into the gender wage gap has found that women experience a gradual but continual rise in the gap once they have their first child.

The study also found, on average, that the hourly wages of female employees are currently about 18 per cent lower than men’s. This means that overall the wage gap is on a downward (albeit slow) trajectory as women’s wages were 23 per cent lower in 2003 and 28 per cent lower in 1993.

However, the wage gap is not static over the life cycle. For instance, the gap is relatively small or non-existent around the time of labour market entry and widens only slowly up to the mid 20s (and especially slowly for graduates).

The gap starts to open up around the late 20s and gets gradually wider over the next 20 years. This is because male wages continue to increase, especially for the highly-educated, while female wages flatline on average. The study’s authors assume that the gap occurs because of the arrival of children.

Indeed figures produced by the study show that the gender wage gap widens dramatically in the years after the arrival of the first child. There is, on average, a wage gap of over 10 per cent even before the first child arrives, but this gap appears fairly stable until the child arrives and is small relative to what follows.

There is then a gradual but continual rise in the gap over the following 12 years, until it reaches a plateau of around 33 per cent. The authors also note that once the employment gap opens up after the arrival of the first child, it is persistent.

A big difference in employment rates between men and women also opens up on arrival of the first child and is highly persistent. By the time their first child is aged 20, women have on average been in paid work for four years less than men and have spent nine years less in paid work of more than 20 hours per week.

Jo Seery, of Thompsons Solicitors, said: “The research confirms that women continue to bear the cost of childcare by either taking time out to look after children or as a result of flexible working. What is shocking is the extent to which the pay gap increases during a woman’s working life. If the Government is serious about tackling the gender pay gap it will need to ensure that the proposed gender pay gap regulations, which will require employers to publish gender pay information sufficiently detailed to encourage employers to take action to address the causes of unequal pay.”

To read the full report, go to: https://www.ifs.org.uk/uploads/publications/bns/bn186.pdf