Hundreds of studies have attempted to estimate what is known as the ‘motherhood pay gap’ and to identify its causes. Most find that a motherhood pay gap does exist, and tends to widen with the number of children. For every child a working woman has, her ability to keep pace in earnings with her childless peers loses traction. Mothers with two children, for example, may earn 25% less than women without children.
However, the size of the gap is not the same in all countries. In some, mothers seem to experience a one-off penalty on return to employment and soon catch up in earnings, while in others the penalty seems to cumulate over time. Most research still finds a gap in mothers’ pay even after controlling for differences in education, work experience and occupation. Motherhood gaps also tend to be larger in developing countries than in developed countries.
We reviewed research on women’s pay across the globe, but it was here in Britain that mothers working full-time are among the hardest hit, due to a lack of available facilities to care for children after school or during the working day. Women who have their children young – aged 25 and under – and those who take longer leave from work also experience longer lasting wage penalties.
Turning to the reasons behind the motherhood pay gulf, we identified and examined three types of explanations – economic, sociological and institutional. Economic explanations focus on a mother’s commitment and productivity once she returns to work after having children. It is also suggested that her skills may have depreciated due to the interruption in working patterns – particularly if new innovations have been developed during her absence.
Added to this, some argue that mothers may choose to return to work in ‘family-friendly’ jobs, which might offer greater flexibility but could be less productive and hence lower paid. However, many of these explanations rely on assumptions by managers that women become less productive or committed, and do not necessarily reflect hard evidence of differences in performance or motivation.
Sociologists point to the negative stereotypes about mothers’ commitment to work that exist, and demonstrate how such preconceptions can shape an employer's hiring and promotion decisions, rightly or wrongly. The failure of local markets to provide suitable levels of childcare to support mothers in paid employment has also contributed to the pay gap.
Institutional factors, which may help explain the wide differences in the size of the motherhood pay gap across countries, include differences in welfare state provisions (for example childcare, maternity/paternity leave, tax and benefits).
In the report we make a number of policy recommendations in order to redress the gap between the pay of working mothers and their childless peers. In the UK, reducing the wage penalty can be greatly assisted by the following measures:
• Improve the statutory level of income-related pay for mothers and fatherstaking leave
• Make childcare more accessible, better quality and affordable
• Adjust tax credit rules so that mothers are treated as economically independent adults, not second earners
• Proactively counter negative stereotypes about mothers’ commitment to paid employment
• Encourage family-friendly workplace cultures
While there are now opportunities in the UK for mothers and fathers to share paid leave (although the pay is still very low), the cost of childcare continues to impact on a parent’s decision to go back to work full-time or part-time, therefore exacerbating the motherhood pay gap.
Some businesses do take the wider family welfare of their employees seriously, helping parents to progress their careers while managing a family life. Major employers such as the BBC and John Lewis have signed up the Workingmums.co.uk Top Employers' Charter as a statement of their commitment.
Businesses with a large share of women in their workforce in particular, could benefit from following the example set by such businesses. The result would be more engaged employees thanks to greater flexibility and more scope for career progression.
Damian Grimshaw is director of the European Work and Employment Research Centre at Manchester Business School. Jill Rubery is professor of comparative employment systems at Manchester Business School