Does the Workplace Penalise Women for Being Mothers?

Back in 2017, I came across the term ‘Motherhood Penalty’ while conducting research on the gender wage gap. I was curious about why women tend to earn less than men on average – even if they hold the exact same position with the exact same level of skills and experience…

The South African labour market is more favourable to men than it is to women regardless of race. Women accounted for about 43,8% of total employment in the second quarter of 2018.  Since most women tend to change their labour-market behaviour more drastically in response to a change in family/children size than men, I decided to dig deeper to understand how much of this gap in salaries had to do with the incidence of motherhood amongst women.

Do women with children earn less than women without children in the South African labour market? I examined whether there exists a motherhood (or child) penalty for Black female employees in post-apartheid South Africa using two cross sections of data from the National Income Dynamics Study (NIDS) for the years 2008 and 2014. NIDS is the very first nationally representative survey in South Africa to include comprehensive child birth history.


In the research, mothers are defined as women with at least one biological child residing with them in the household. Non-mothers are women with no biological children, and also includes women who may have child(ren) but do not reside with them. Due to the prevalence of migrant work in South Africa, this is an important element to note when considering the economic decisions of Black women. This classification is thus designed in order to measure the effect of care work on women who are currently employed. From the NIDS survey, about 82% of working women between the ages of 20 and 49 are mothers. Restricting analysis to Black women aged 20 to 49, the regression model results indicate that a motherhood penalty does exist, ceteris paribus. In addition, the more children a woman has, the heavier the penalty. In other words, there is a clear association between being a mother and earning lower wages than non-mothers (child-free women).

The study goes further by applying unconditional quantile regressions (RIF-OLS) to examine the wage returns of mothers versus non-mothers along the wage distribution (at different salary points). This is to determine whether the pay gap between mothers and non-mothers is worse at lower wage levels, or vice versa. The results reveal that there exists a stark motherhood wage penalty at lower wage levels, and this effect wanes in prominence at higher wage brackets. Moreover, at higher wage levels, mothers earn higher wages than their child-free counterparts, especially if they are married. This outcome might have to do with the effect noted by Kahn et al. (2014) who found that motherhood has the strongest negative labour market outcomes for women when they are younger (and earning less) and then attenuates when they are older (around age 50). In other words, the motherhood penalty is worse for single Black women who lie at the lower end of the income distribution.

What about the discrimination factor? Employers might deem mothers to be less productive because of work experience foregone to take care of children. [Of course, this assumes the generic parenting arrangement where women bear childcare over men]. International studies show that given identical résumés (CV’s), mothers were less likely to be recommended for hire or promotion; offered marginally significantly lower starting salaries; and held to higher performance and punctuality standards.


Consequently, my study applied Oaxaca-Blinder type decompositions within the RIF framework to decompose changes in the motherhood wage gap along the distribution into explained and unexplained contributions related to a range of factors. The unexplained part is usually seen as a measure of discrimination. The decomposition results indicate that at the 10th and 90th quantiles (lowest and highest wage points respectively), the wages of mothers minus wages of non-mothers is negative (on average), but positive everywhere else. Simply put, at the bottom and at the highest income brackets, there exist clear wage penalties for motherhood.

Interestingly, the majority of the wage differential between mothers and non-mothers is due to unexplained characteristics, meaning that there are additional unobservable but relevant factors such as societal norms, selection effects into employment and behavioural characteristics affecting women’s wage outcomes.

Discrimination may be the reason why women don’t even bother working in certain positions: they may engage in part-time employment, or reduce working hours or even change occupations completely. Likewise, it is possible that women with children may have anticipated in the past that they want to have kids and therefore self-select into more flexible occupations. For the case of low-skilled women in South Africa today, occupation selection is also based on what jobs become available. For example, most women work in the services industry and in private households (e.g. domestic work).


The research does acknowledge that amongst high skilled (more educated) wage earners, motherhood might have a less pronounced effect on earnings differences. Therefore, the motherhood penalty does exist, especially at lower wage levels; furthermore, motherhood may influence both employment decisions and their vulnerability to discrimination.

Even though being a mother has an effect on wages, what is more striking about the results is that women – both mothers and child-free women – in general carry social norms and prejudices against them. How the workplace adjusts to childbearing and child-caring matter: but how the workplace adjusts to the presence of women matters more.

This study is important because there is a growing tendency globally for career-minded and highly skilled women to postpone or even forgo child-bearing for the sake of career progression. Legal or statutory support for work-care arrangements in South African organisations is weak. Fostering a respectful and inclusive culture so women feel safe and supported at work is a pertinent objective.


Please share your experiences and thoughts on the topic by commenting below.

To read the full research paper, visit:


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