Child penalties

Child penalties (also known as motherhood penalty) refer to the negative impact of parenthood on women’s labor market outcomes relative to men’s. After childbirth, women’s employment rates, working hours, career progression, and earnings tend to decline sharply relative to men’s outcomes. These penalties are central to understanding gender inequality in the labor market, explaining most of the earnings gap in many high-income countries.

Research shows that long-run earnings penalties are around 20% in Nordic countries, 30–40% in the U.S. and U.K., and over 50% in Germany, Austria, and Switzerland. While policies like job-protected parental leave and childcare may help, child penalties are primarily shaped by labor market structure and gender norms.

The magnitude and persistence of child penalties have made them central to the debate about the gender pay gap. In Denmark, for example, the fraction of the gender pay gap explained by parenthood increased from about 40% in 1980 to over 80% by 2013. To address this issue, policymakers have proposed solutions such as shared parental leave, affordable childcare, flexible work arrangements, and shifts in societal norms.

History

Early developments

Early origins of the debate can be traced back to Gary Becker’s A Treatise on the Family (1981). Becker argued that women earn less than men because childbearing interrupts their careers and reduces human capital accumulation. In the 1990s, empirical studies provided early support: Waldfogel (1998) and Lundberg and Rose (2000) documented a family gap in the U.S. and U.K.: mothers earned 10‑15 % less than comparable women without children. Sociological work emphasized discrimination; Correll, Benard & Paik (2007) found hiring bias against mothers.

Modern approach

In the late 20th century, women delayed childbirth, surpassed men in college enrollment, and dual-earner household became the norm. Yet the gender pay gap persisted. This opened the question of how much of the gender gap is caused by parenthood, and what explains the gendered effects of parenthood?

Answering this required tracking both partners before and after childbirth. A methodological breakthrough came when Henrik Kleven, Camille Landais, and collaborators developed an event-study approach using administrative registers that follow workers over time. In their landmark study, Kleven, Landais & Søgaard (2019) show that, in Denmark, men and women have similar earnings trajectories until the birth of their first child, but diverge sharply after childbirth. Women’s earnings fall by about 20% relative to men’s and never catch back up. This “child penalty” captured the causal effect of parenthood on gender inequality. Subsequent work has replicated this pattern in many countries. Where panel data are unavailable, Kleven (2025) developed a pseudo-event study method using only cross-sectional data. By 2024, child‑penalty estimates existed for over 130 countries, revealing large cross-country variation but a consistently unequal impact of children on women’s earnings.

Key conceptual developments

This figure presents one of the first empirical estimates of the child penalty for Denmark. Source: Kleven, Landais & Søgaard (2019).

1. Research question: Traditional gender gap studies focused on unequal pay for equal work. This is the degree to which men and women are paid differently conditional on having the same education level, job market experience, and occupation. This gap was typically interpreted as a measure of discrimination. Over time, this gap has become relatively small in high-income countries. Child penalty research asks a different question: What is the impact of children on women’s and men’s labor market outcomes – such as earnings or employment – not conditioning on things like education and occupation. This research highlights that gender inequality persists even with equal pay for equal work, largely due to parenthood.
2. Methodology: Modern research typically uses an event-study approach, capturing how gender gaps evolve dynamically around childbirth. The approach proposed by Kleven, Landais, and Søgaard (2019) has become the standard way of estimating child penalties.
3. Explanations: The literature has moved beyond traditional explanations for gender gaps such as human capital and discrimination, highlighting household specialization, workplace flexibility, social norms, and family policy.
4. Geographic scope: Extends the scope from single-country studies to global comparisons, connecting child penalties to broader cultural and economic contexts.

Measurement

Child penalties are measured by comparing women’s and men’s labor-market outcomes before and after the birth of a first child. The standard empirical framework is an event-study, which compares labor market outcomes—such as earnings or employment—over time, relative to the moment of childbirth. In this setting, the “event” is the birth of a first child.

Event study specification

The event-study framework builds a timeline around childbirth, labeling each year before and after the event. The year of birth of the first child is denoted as event time $t=0$. Years before childbirth are indicated by negative numbers (e.g., $t=-1$ is one year before birth), and years after childbirth are indicated by positive numbers ($t=1$ one year after birth, $t=2$ two years after, and so forth). The method tracks how outcomes evolve over time for mothers and fathers, estimating average changes at each point relative to the year before birth. Results are computed separately by gender, allowing researchers to compare how childbirth affects women and men differently.

Formally, the event-study regression can be represented as:

$Y_{it}^{g}=\sum _{j}\alpha _{j}^{g}\cdot {\text{EVENT}}_{j=t}+{\text{age/year dummies}}$

where:

• $Y_{it}^{g}$ is an outcome (such as earnings or employment) for individual $i$ of gender $g$ in year $t$.
• ${\text{EVENT}}_{j=t}$ is an indicator that equals 1 if the year is exactly $j$ years from childbirth, and 0 otherwise.
• $\alpha _{t}^{g}$ measures the average change in the outcome for gender $g$ at each event time $t$, relative to a reference year (commonly one or two years before birth, $t=-1$ or $t=-2$).
• The age and year dummies control for lifecycle and time trends unrelated to parenthood.

The key assumption underlying this method is that, without the birth of a child, women’s and men’s outcomes would have followed the same trend. This is known as the parallel trends assumption. Researchers validate this by checking that the trends for women and men do not diverge in the years before parenthood.

Interpreting the results

The estimates from event studies are usually shown in graphs, with one line for women and another for men. Before birth, both lines tend to follow similar paths. After birth, the line for women typically shows a sharp and persistent decline, relative to men’s.

To make the results easier to interpret, researchers often convert the effects on earnings or labor supply into percentages. If we label the percentage effects on men and women by $P_{t}^{m}$ and $P_{t}^{w}$, respectively, the child penalty is typically defined as follows

${\text{Child Penalty}}=\mathrm {E} [P_{t}^{m}-P_{t}^{w}\mid t\geq 0]$

This expression represents the average difference in the percentage effect of parenthood between men and women.

Evidence on child penalties

General pattern

Event-study analyses reveal a consistent pattern: Men and women follow similar labor market trajectories until the birth of a first child, after which women’s earnings and employment decline sharply, while men’s remain relatively stable. In the United States, for example, mothers earn about 36% less than men due to the unequal effects of parenthood.

Child penalty in Earnings, United Kingdom

Child penalty Earnings, United States

The penalties persist over time and tend to increase with each additional child. This divergence has been documented in over 130 countries, suggesting a robust empirical regularity.

Cross-country differences

While the child penalty phenomenon is nearly universal, its size varies across countries and institutional contexts. Kleven et. al (2019) found long-run earnings losses for women of 21–26% in Denmark and Sweden (Nordic welfare states), 31–44% in the U.S. and U.K. (Anglo-American economies), and up to 51–61% in Germany and Austria (more traditional breadwinner model countries). In all cases, men’s earnings were mostly unaffected.

Child penalties in employment across 134 countries, Child Penalty Atlas Project

The Child Penalty Atlas of 2024 extended these findings to 134 countries, revealing wide variation: Penalties are generally larger in richer economies and smaller in poorer ones. As economies develop and labor market structure changes, child penalties become a key source of gender inequality. Historically, the gap once emerged at marriage; today, it is primarily driven by childbirth. Even in countries with generous family policies, penalties persist.

Contribution to gender inequality

Because child penalties are so large and persistent, they are a major driver of gender inequality in labor markets, especially in countries where men and women are otherwise similar in education, experience, and legal rights. In Denmark, 80–90% of the post-30 gender earnings gap is due to children. In the U.S., recent studies attribute nearly all remaining gender inequality in labor force participation and pay to parenthood. Other explanations – like unequal pay for equal work – have declined in relevance.

As Bertrand (2020) notes, motherhood has become a dominant source of gender inequality in high-income countries as women’s career trajectories diverge from men’s after childbirth. Across contexts, child penalties consistently explain women’s lower earnings and underrepresentation in top positions.

Causes

Biological factors

The physical demands of pregnancy, childbirth, and breastfeeding explain short-term career interruptions, but not the long-term earnings gap. Studies show that adoptive mothers face nearly identical child penalties as biological mothers, suggesting biology alone cannot account for the persistent divergence. Even without physical necessity, adoptive mothers often become the primary caregivers.

Comparative advantage

Becker’s theory posits that families specialize based on comparative advantage, with the lower earner taking on childcare. But even when women out-earn their partners pre-birth, they are more likely to reduce work and suffer earnings losses post-birth. Thus, relative earnings alone do not explain child penalties.

Public policies

Government policies like parental leave and subsidized childcare help with short-run labor market impacts of childbirth, but they have done little to reduce long-term penalties. Studies from across different countries suggest that even very generous family policies have a limited impact on women’s cumulative earnings losses.

Gender norms and culture

Gender norms and cultural expectations are central to understanding child penalties. In cultures where caregiving is primarily viewed as a maternal responsibility, women disproportionately adjust their employment after childbirth, often irrespective of economic incentives.

Cross-national comparisons support this connection between traditional gender roles and greater child penalties. Blau, Kahn, and Papps (2011) demonstrate this through their analysis of immigrant women in the U.S., whose labor market participation after childbirth aligns closely with gender norms from their countries of origin. Importantly, immigrant men's employment behaviors remain unaffected by these norms, underscoring the gender-specific nature of this phenomenon.

Studies of same-sex couples provide further evidence on the role of gender norms in shaping child penalties. Research on lesbian couples from Norway finds no earnings penalty for the biological mother relative to the co-mother. This indicates that, when gender is not a factor, childbirth does not create inequality within couples. These patterns point to social expectations around gender roles—rather than biology—as central to understanding how parenthood affects labor market outcomes. Survey research reinforces the role of societal expectations. Kuziemko et al. (2018) found that women's preferences regarding family and work shift significantly after childbirth, reflecting internalized societal norms rather than purely economic considerations.

Kleven (2025) provides evidence that child penalties are shaped by gender norms by studying movers and immigrants in the U.S. Child penalties vary considerably across states, correlating closely with regional differences in gender norms. The child penalty for movers is strongly related to the child penalty in their state of birth, and the child penalty for foreign immigrants is strongly related to the child penalty in their country of birth. For example, immigrants born in high-penalty countries like Bangladesh or Mexico have much larger child penalties in the U.S. than immigrants born in low-penalty countries like China or the Nordic countries.

Labor market structure

Labor market institutions and job characteristics also matter. Goldin (2014) highlighted that “greedy” careers—those requiring long, inflexible hours and constant presence—tend to impose heavier penalties on mothers. After childbirth, mothers often seek flexibility, trading off earnings for family friendliness. Flexible occupations like pharmacy jobs, exhibit smaller or no penalties. The work structure thus plays a key role in reinforcing or mitigating the impact of parenthood on women’s careers.

Are child penalties causal?

A key question is whether child penalties reflect a causal impact of having children or are driven by unobserved differences between individuals that decide to have children at different times. The event study design addresses this concern by showing that men’s and women’s career trajectories are nearly identical before childbirth, diverging sharply just after childbirth, suggesting a causal effect of parenthood. While small “anticipation effects” may exist, most of the gap emerges after childbirth.

A potential concern is that women might already be adjusting their careers in anticipation of future motherhood—for example, by avoiding demanding jobs or working fewer hours even before having children. These so-called “anticipation effects” could mean that part of the penalty is happening earlier, before childbirth. However, studies have shown that modern cohorts of men and women typically start their careers on very similar trajectories. Any pre-birth differences tend to be small, and the majority of the gender gap in earnings emerges only after the first child is born. This suggests that anticipation plays only a minor role, and that most of the child penalty is directly tied to the event of childbirth itself.

To further validate the causal interpretation, researchers use instrumental variable (IV) strategies. One method exploits the sex composition of a family’s first two children, as parents with same-sex children are more likely to have a third child. Kleven, Landais & Søgaard (2019) found that this IV-based estimate of the third-child penalty matched event-study results closely.

More recent studies have used natural experiments such as unintended pregnancies caused by contraceptive failure. Gallen et al. (2024) found that women in Sweden who became pregnant due to IUD failure faced large, lasting earnings losses, closely mirroring event-study findings. Other studies use In Vitro Fertilization (IVF) outcomes to create instruments, comparing women whose treatment was successful with those whose treatments failed.

Together, these approaches reinforce that children cause significant, lasting career penalties for women relative to men.

Public debate

Over the past decade, research has increasingly shown that the majority of the gender pay gap in earnings and employment arises after childbirth, rather than from direct discrimination or pre-child differences. As a result, closing the gender gap has become almost synonymous with eliminating child penalties in both academic and policy discussions.

Gender Gap Decomposition by three factors: Child penalties, Marriage Gap and Residual Gap.

This shift in understanding has influenced international organizations, national governments, and media discourse. For example, the OECD and the World Bank have explicitly linked family policies to reducing gender inequality, emphasizing the importance of access to childcare and reforming parental leave in major reports on gender equity. Similarly, the United Nations’ ILO has emphasized the role of unpaid care and motherhood-related labor market exits in sustaining global gender gaps.

Policies like parental leave for fathers, childcare availability, labor market flexibility, shifting social norms around childcare, among others, are at the forefront of the public debate about gender inequality caused by childbirth.

In some countries, these efforts are already visible, as they have implemented non-transferable, paid parental leave for fathers (or “father's quotas”). These policies reserve a portion of parental leave exclusively for fathers, incentivizing their participation in early childcare and challenging traditional gender roles.

Global examples of father's quota

• Norway: Introduced a four-week “father’s quota” in 1993, which has since expanded to 15 weeks. This policy led to a significant increase in parental leave uptake, from under 3% to over 70% of eligible fathers taking leave.
• Sweden: Offers 480 days of paid parental leave per child, with 90 days reserved for each parent. This policy has resulted in about 90% of fathers taking some parental leave, contributing to a more equitable division of childcare responsibilities.
• Iceland: Adopted a “6+6” parental leave model in 2021, allocating six months each to the mother and father. This structure increased fathers’ participation in childcare and promoted gender equality in parenting.
• Germany: In 2007, introduced “Elterngeld,” providing 12 months of paid leave at approximately 67% wage replacement, plus two bonus months if both parents share leave. This led to a significant rise in fathers taking parental leave.
• Quebec, Canada: Established a five-week non-transferable paternity leave in 2006, increasing fathers’ leave uptake from 21% to 80%. This policy also positively impacted mothers’ labor force participation.
• Japan: Since 2010, Japanese fathers have had an independent entitlement to leave, meaning a full year is reserved for the father (separate from the mother’s leave). Historically, however, uptake was extremely low due to workplace culture. As recently as 2015, only ~5% of new fathers in Japan took any parental leave.
• South Korea: Provides up to one year of paid parental leave per parent. The introduction of incentives like “Daddy Months” (if both parents take leave sequentially, the second parent (often the father) gets the first 3 months at nearly full pay) has led to a rapid rise in fathers taking leave, with men accounting for 32% of all parental leave takers in the first half of 2024.

See also

• Gender pay gap
• Motherhood penalty
• Parental leave
• Henrik Kleven
• Camille Landais