Second Child, Bigger Pay Gap: How Births Reshape Wages in China

When a baby arrives, the paychecks of its parents rarely move in the same direction. A new study of Chinese urban workers finds that after a first birth, women’s annual wages fall by roughly 11 percent while men’s rise by nearly 5 percent. After a second child, the divergence deepens dramatically: mothers lose close to 19 percent of their annual wages, while fathers gain almost 13 percent. The research, published in Frontiers in Sociology, offers one of the most detailed portraits yet of how successive births carve a widening chasm between men’s and women’s earnings in the world’s second-largest economy.

The study, led by Chong Guo of Suzhou Vocational University and colleagues at Nanjing University of Agriculture and Henan Agricultural University, draws on four waves of the China Household Finance Survey conducted in 2013, 2015, 2017, and 2019. The survey, administered by Southwestern University of Finance and Economics, uses stratified multistage probability sampling across 29 provincial units of mainland China. After restricting the sample to urban respondents with complete fertility information and applying consistent marriage and retirement criteria, the researchers assembled an analytical panel of 38,174 observations spanning women aged 20 to 55 and men aged 22 to 60.

What makes the study methodologically distinctive is its treatment of childbirth not as a single event but as two separate transitions: the move from no children to one child, and the move from one child to two. Because Chinese families experienced childbirth at different calendar times, the researchers faced the problem of staggered treatment timing, a well-known pitfall in difference-in-differences analysis. To address it, they combined a conventional difference-in-differences framework with the Callaway and Sant’Anna group-time estimator, which computes treatment effects separately for each birth cohort and survey year before aggregating them. They supplemented this with event-study analysis tracing wage trajectories from three years before to fifteen years after each birth, Heckman selection correction to account for the fact that wages are observed only for the employed, and Oster’s coefficient-stability method to probe sensitivity to unobserved factors.

The baseline results are striking in their symmetry of asymmetry. After the first birth, women’s annual wages drop by approximately 10.95 percent while men’s climb by 4.92 percent. After the second birth, the motherhood penalty roughly doubles to 19.18 percent, and the fatherhood premium more than doubles to 12.75 percent. When the researchers pooled women and men into a single specification with a gender interaction term, the contrast coefficients were negative and highly significant for both transitions, confirming that the wage effect of childbirth is systematically less favorable for women. Formal tests comparing the two transitions showed the second-birth estimates were significantly more extreme for both sexes.

The event-study analysis provided a crucial validation. In the years before childbirth, the estimated coefficients for both women and men were statistically indistinguishable from zero, with joint tests failing to reject the null of no pre-trends. This parallel-trends check is essential for the credibility of difference-in-differences estimates, since differential wage trajectories before treatment would suggest that the estimated effects reflect pre-existing differences rather than the causal impact of childbirth. After the birth, the coefficients turned negative for women and positive for men, with magnitudes generally larger around the second transition, particularly for mothers.

Why would a second child exact a heavier toll? The researchers point to mechanisms involving working hours, employment continuity, and career progression. Women with two children reported significantly shorter weekly working hours than childless women, a pattern not seen after the first birth. They were also more likely to have experienced employment interruptions and less likely to hold leadership or managerial positions. Men showed the mirror image: fathers of two worked longer hours and enjoyed more continuous employment than childless men. These patterns are consistent with a gendered reallocation of household labor, in which rising childcare demands push women out of paid work while breadwinner norms pull men deeper into it. The authors caution that these channel analyses are suggestive rather than causal, but they align with a substantial international literature on child penalties.

The study also identified conditions that soften the blow. Households with family support, defined as a spouse earning above the sample mean or spending on domestic services, showed significantly smaller motherhood penalties and larger fatherhood premiums. Digital finance emerged as another moderating force, measured both at the individual level, through use of services such as Alipay or WeChat Pay, and at the regional level, through the Peking University Digital Financial Inclusion Index. Women who used digital financial services and those living in regions with more developed digital finance experienced smaller wage losses after childbirth. The authors suggest that digital finance eases financial constraints, lowers transaction costs, and may strengthen women’s bargaining power within households, helping them remain economically active after becoming mothers.

Institutional context mattered as well. The wage effects were generally larger in absolute terms among workers outside the state work unit system and among those without establishment status, a distinctive form of employment in Chinese government agencies and public institutions that carries formal personnel rules, greater job security, and standardized pay. Women inside the system faced smaller penalties, and men outside it enjoyed larger premiums, though some group differences were statistically significant only at particular parities. The researchers note that the wage sample covers only employed respondents, so the full disadvantage for women outside protected employment may be understated, since those who exit the labor force entirely are not captured in wage data.

An Oaxaca-Blinder decomposition of the gender wage gap revealed a sobering picture. Observed individual characteristics, such as education, age, and health, actually narrow the average gap between men and women, meaning that women’s observable qualifications are, if anything, favorable relative to their pay. The unexplained component, which captures coefficient differences and factors not measured in the survey, such as potential discrimination, labor market segmentation, and gender norms, is what widens the gap. Within couples, both birth transitions were associated with wider earnings gaps between husbands and wives, with the second birth producing an increase of more than 10,000 yuan in the annual earnings gap, roughly double the first-birth effect.

The findings arrive at a moment when China is actively encouraging fertility, having moved from the one-child policy to a universal two-child policy in 2016 and a three-child policy in 2021. If the wage consequences of childbirth fall so heavily and asymmetrically on women, the authors suggest, policies that support continued employment after childbirth, including affordable childcare, employment protection, and greater paternal involvement in care, may be essential not only for gender equality but also for the success of pro-natalist goals. The study’s limitations are acknowledged: four survey waves offer only a limited window around childbirth, and fertility timing may correlate with unobserved traits. Still, the message is clear. The child penalty is not a one-time shock but a compounding one, and each additional birth deepens the economic divide between mothers and fathers.

Subject of Research: The impact of first and second childbirths on the gender wage gap in urban China

Article Title: The impact of childbirth on gender wage gap: evidence from China

Article References: Guo, C., Pan, X., Wang, Y., & Xie, M. (2026). The impact of childbirth on gender wage gap: evidence from China. Frontiers in Sociology, 11, Article 1887787. https://doi.org/10.3389/fsoc.2026.1887787

Image Credits: AI Generated

DOI: 10.3389/fsoc.2026.1887787

Keywords: gender wage gap, motherhood penalty, fatherhood premium, childbirth, China, China Household Finance Survey, difference-in-differences, digital finance, family support, labor market, fertility policy, child penalty