How does economic disadvantage accumulate for single mothers?

In Episode 7 of Series 2 of our podcast we talk with Professor Susan Harkness from the University of Bristol and PI of DIAL’s EQUAL LIVES project about how economic disadvantage accumulates for single mothers and the impacts on their income and risk of poverty of having a child and splitting up from a partner.

The Accumulation of Economic Disadvantage: The Influence of Childbirth and Divorce on the Income and Poverty Risk of Single Mothers is research by Professor Susan Harkness of the University of Bristol and is published in Demography.



Christine Garrington  0:00

Welcome to DIAL a podcast where we tune in to evidence on inequality over the life course. In this series, we discuss emerging findings from DIAL’s Equal Lives project. Our guest today is Professor Susan Harkness from the University of Bristol and PI of Equal Lives. She’s been looking at how economic disadvantage accumulates for single mothers, and the impacts on their income and risk of poverty of having a child and splitting up from a partner. I started by asking her about the background to her research.

Susan Harkness  0:28 

I think for a long time, there’s been an assumption that single mothers are more likely to be poor or living in low income because they’re not living with a male breadwinning partner. And I think one of the things that’s been much less well recognised is that in the US, but also elsewhere, single mothers are much more likely to be poor than single fathers and I think one of the reasons for this is not just that they don’t live with a partner, but also because they face an enormous economic hit because of motherhood. And I think the motherhood penalty. We know, we know it exists. We know mothers are much less likely to work than fathers. And when they do work, that they’re more likely to be paid less. And what I wanted to do was try and connect to this research with research from single parenthood to see what the impact on single mothers’ incomes was.

Christine Garrington  1:16 

So what was it here that you wanted to look at specifically and why then?


Susan Harkness  1:21 

Okay, so I wanted to think about why single mothers were more likely to have low income so what was the penalty to single motherhood? And in doing that, I wanted to think about single motherhood is a process that sort of evolves over the life cycle. So first of all, we know that mothers when they have children, they face this economic penalty in the labour market, and then when they separate, they’re left in this very vulnerable position because their employment earnings have just declined so much.

Christine Garrington  1:49

And for this research, where did you get your information from? And can you tell us sort of why it is a good source for for looking at these particular issues? 

Susan Harkness  1:58 

Yes, so we looked at data from the Panel Study for Income Dynamics and it’s a great source of data because it allows us to look at people over time. In the case of our study, we’ve followed them for over 10 years, since becoming mothers to look at what happened to their incomes around these kind of critical lifecourse transitions. One of the great advantages of it is that we can see how people were doing before they became single mothers and we can see how they were doing after and then we can kind of look at how each of these different life course events – motherhood, partnership dissolution – leads to changes in their economic circumstances. Another major advantage of this data is that it’s got a really large sample size, and therefore we can think a bit more also about the heterogeneity the experience of single mothers. And what we mean here is that we can think about whether all single mothers effectively look the same or whether different routes into single motherhood have a different impact on their incomes. So what we did in this particular case was think about how single mothers differ according to whether they were previously married. They were previously cohabiting, or indeed they were married at the time at which they had a child. And this is a group which is accounting for a sort of growing share of births in the US and indeed in the UK over time.

Christine Garrington  3:18 

Right now you started by comparing the incomes of single, cohabiting and married mothers, what did you, what did you actually see there?

Susan Harkness  3:26

So one thing that we see is, is I think fairly fairly well known but we know that for example, married mothers start from a position of having higher incomes than cohabiting mothers and single mothers. So there’s an income gradient with cohabiting mothers sitting somewhere in the middle. But what we also know is that the, the income composition of those families is quite different. So whilst in single mother families, women are indeed largely dependent on their own earnings, and to some extent on benefit receipts, in cohabiting and married mother families, there’s a much greater dependence of women on partner’s earnings. And indeed if you look at the earnings, of women within those different family types, they’re actually relatively similar. Married and cohabiting mothers tend to be more dependent on partners, whereas single mothers tend to be more dependent on their own earnings and on the state. 

Christine Garrington  4:22

Yeah, right – so what was the earnings impact of divorce or separation for each of these groups and were they larger for some than, than others?

Susan Harkness  4:29

Okay, so one of the things that we thought was really interesting is that if we look at what happens to women’s own earnings following the birth of a child, the biggest negative effect was for women who were previously married. So we’re not looking at wage effects specifically we’re looking at the combined effect of changes in wages and changes in working hours and indeed participation. What we see is that for married mothers, we find much greater reduction in self-sufficiency or increased economic dependence as a result of childbirth, amongst cohabiting mothers, among single mothers, we see a smaller earnings effect, so earnings declined by less. And what happens then if we look at the income within those families, is that if we consider what happens to the income of married mother families? In fact, what we find is that although earnings fall quite substantially amongst married mothers, these are compensated for by increases in fathers’ earnings who to tend to work longer hours and work more often when they have a child and therefore the overall impact on income is relatively small, whereas in single mother families, the birth of the child is associated with the fall in earnings and a really large impact on overall income.

Christine Garrington  5:42

Okay, and you also considered how the loss of a male partner’s income affected these separated and divorced mothers, what did you see there?

Susan Harkness  5:49

So what we see for the loss of a partner’s earnings is of course, married mothers tend to be partner to higher earning men and men who work more following the birth of a child and so when the partner leaves, we have a larger negative effect on their overall incomes. And part of this is because of the reduction in these married mothers’ own earnings following childbirth. And part of the reason for that is that the, they have, they have farther, further to fall. So the, the loss of father’s earnings fall this is somewhat greater.

Christine Garrington 6:19

Yeah, so quite a lot of information there. What do we learn from all of this? That’s new, Susan?

Susan Harkness  6:24

If we think about what happens within married couples, I think because marriage sort of provides some security, is thought to provide some security for those who have children that we tend to see greater levels of specialisation within those households. What this means is that women see their earnings fall farther than cohabiting are single mothers, and it becomes harder for them to recover those earnings should they, should they separate so the overall impact should they become single mothers on their own labour market income is greater than for these other family types. And what does this mean? It means that actually the separation from marriage tends to have worse consequences than it does if you become a single mother through separation from cohabitation or divorce. Whilst you might think, for example, that maintenance might help offset some of these costs associated with divorce. In fact, this is often not really, not really the case because the levels of maintenance payments are relatively small. What we find is actually that single parenthood, regardless of the route in by which you become a single mother, is really quite a leveller and women who were better off before see the largest falls in their income.

Christine Garrington 7:42

Okay, there was one other aspect of your research that really caught my eye and this was, these were your findings around what things are like for single moms who are living with parents. These are quite interesting, weren’t they?

Susan Harkness  7:51

Oh, I think this is, this is fascinating. So one of the things that I think increasing research is looking at is how, how single mothers maintain those sort of standard of, standard of living, when they’re not able to rely on their own earnings or indeed on the state. And we know that in the US around one in 10 single mothers are living with their own parents. And in in this study, we find that actually living with your own parents is a really important mechanism for boosting families’ income. And in fact, living with your own parents provides as much protection for household income as being married and a little more than if you find a new partner, for example. So it’s really, really important living with grandparents is a really important route to kind of maintaining your standard of living following parental separation. 

Christine Garrington 8:42

Important to acknowledge that the very rich data you used here is from the US but I wonder if you think that the picture might be reflected in the in the UK, where we are, and also possibly in other parts of Europe?

Susan Harkness  8:54

Yes, absolutely. So one of the things we know about the UK is that and indeed other parts of Europe is that motherhood is associated with even larger reductions in overall labour supply. So we know that women when they have children are perhaps less likely to work but also much more likely to work part-time. So the the numbers that are working full time are far lower, after having children in the UK and other European countries, many other European countries than in the US. So what we would expect to find is actually that the impact of single motherhood on income is going to be quite different. So in the case of in the case of the UK, what we might expect to see is that it sees large losses in earnings associated with losses in employment for motherhood, are probably going to have an even larger impact on their well being – their economic well being – should they, should they subsequently divorce. But on a more sort of positive note, I think what we have in many European countries is greater welfare support for, for single mothers which is, is much more significant for boosting their incomes. Although of course this has the further drawback that it can also discourage women from working or working longer hours because of the design of various welfare support systems.

Christine Garrington 10:18

Yeah, indeed. Now single mothers are a key area of interest for you as a researcher but also a really important group of people that policymakers are interested in and your research would seem to have quite clear and important ramifications and implications for welfare policy. Could you talk us through what you think those modifications are?

Susan Harkness  10:40

Yeah, so I think what one of the things we often see focused on when we think about single parents is what to do about father absence, in particular, how to make fathers pay maintenance, for example. But what our findings are suggesting is that actually, when we think about how to support single mothers incomes, we need to go much further than that. And in particular, one when we think about, for example, welfare to work policies, which focus on single, single mothers. It’s really the case that in my view, that these policies are something that happened far too late in the life course. So if mothers have already lost their jobs and their earnings potential has already been weakened as a result of motherhood, then trying to do something about that at the point at which they divorce seems to me to be far too late. If we look at other studies, more recently, they suggest that when mothers do well, those in single parent families do well as well. And if we think about policies to ensure that women are able to maintain their economic position after having children in the labour market, then we would want to think much more widely about policies such as childcare provision, which would allow mothers to work, reduce their economic dependence and improve their prospects should they separate.

Christine Garrington  12:00 

“Accumulation of economic disadvantage: the influence of childbirth and relationship breakdown on mother’s income and poverty risks” is research by Susan Harkness and is published in Demography. You can find out more about the Norface funded Equal Lives project at, and about the wider DIAL programme at Thanks for listening to this episode of our podcast which is presented and produced by Chris Garrington, edited by Elina Kilpi-Jakonen.