The motherhood penalty (also called the child penalty) is the earnings and labor force penalties women in many industrialized nations experience when they have a child. Although the presence of lower earnings for mothers versus non-mothers (both fathers and women without children), has been established for decades, newly available longitudinal administrative earnings datasets have allowed a flourishing of research on the timing of these penalties.
There exists a universal decline in women's earnings and employment around childbirth, though the magnitude of that decline and the pattern of recovery vary across countries and across women with different characteristics within those countries.
- Albrecht, Bronson, Thoursie, and Vroman (2018)  use employer-employee matched data to explore employer-based heterogeneity and transitions after childbirth, using data from Sweden and focusing on men and women with degrees in business or economics. They show that men are more likely to switch employers and are more likely to benefit from that switch after they have had a child than women.
- Angelov, Johansson and Lindahl (2016)  find that couples in Sweden experience a 32 percentage point increase in the within-couple male-female earnings gap fifteen years after the first birth, driven in part by an increase in the wage gap of ten percentage points. They hypothesize that the institutional environment in Sweden that encourages part-time work until the child reaches the age of 8 contributes to the increasing gap between fathers' and mothers' wages over time.
- Moberg (2016) finds that same-sex female couples experience a smaller change in the spousal income gap after childbirth than different-sex couples.
- Kleven, Landais, and Søgaard (2021)  compare biological and adopted families and find there are large and persistent effects of children on gender gaps in both family types. The short-run impacts are somewhat larger in biological families, but the long-run impacts are virtually identical.
- Kleven, Landais, and Søgaard (2019)  show that in Denmark there is a 19.4% penalty for mothers relative to fathers ten years after the birth of the first child. They find that this increase in the gender gap is driven equally by labor force participation, hours of work, and wage rates.
- Lundborg, Plug, and Rasmussen (2017)  use in vitro fertilization (IVF) in the Danish register data as a natural experiment, comparing women who have a child using IVF to those whose first IVF treatment did not produce a child. They analyze outcomes in the medium run (2-5 years after birth) and long-run (6-10 years); using both time horizons, mothers earn 11-12 percent less. Effects are larger in the short run, driven by a seven percentage point decrease in labor force participation and a 21 percent decrease in hours conditional on participation. However, effects in the medium and long run are due entirely to declines in wages.
- Andresen and Nix (Forthcoming)  show that women in same-sex households experience a smaller earnings penalty when a child is born than women in different-sex households and recovers more quickly, even for the mother who gives birth in the same-sex households.
- Bütikofer, Sissel, and Kjell (2018)  use Norwegian data to show that the earnings penalty is larger and more persistent for those in careers where earnings trajectories tend to be non-linear.
- Killewald and Zhuo (2019)  use sequence analysis to categorize women's employment patterns after childbirth in the U.S., based on the NLSY 1979 cohort. 36% of women generally work full-time, after one month of maternity leave, while 21\% remain out of the labor force for much of the eighteen years after the first birth. The remainder work part-time or take a shorter period of time out of the labor force.
- Neumeier, Sørensen, and Webber (2018) link SIPP survey data to Social Security Administration earnings data to show that the motherhood earnings losses are smaller in recent cohorts relative to childless women, but the implicit costs of motherhood are still large.
- Lu, Wang, and Han (2017) find that of women who were employed before birth, 24% drop out of the labor force or scale back work. Non-white women exhibit greater labor market continuation than white women. For non-native women, labor force attachment was correlated with the length of time in the United States.
- Yu and Kuo (2017) find that the motherhood penalty per child is lower for jobs with greater autonomy and teamwork and higher for jobs that are more competitive.
- Byker (2016)  finds that a substantial (~14 percentage points) share of women in the U.S. leave the labor force when they give birth, and this has been consistent over 3 decades, the 1980s, 1990s, and 2000s.
- Kleven, Landais, Posch, Steinhauer, and Zweimüller (2019)  compare the child penalty estimates for Nordic countries to estimates for German speaking countries (Germany and Austria) and English speaking countries (the U.S. and U.K.) and find that the earnings penalty is larger and more persistent outside of the Nordic countries. Since the mothers in the Nordic countries have more support post-childbirth in the form of paid parental leave and subsidized child care, the estimates for these countries may be a lower bound of potential earnings penalty from fertility.
- Cortés, Patricia and Jessica Pan. "Children and the Remaining Gender Gaps in the Labor Market." Journal of Economic Literature (Forthcoming) Link
- Albrecht, James, Mary Ann Bronson, Peter Skogman Thoursie, and Susan Vroman. "The career dynamics of high-skilled women and men: Evidence from Sweden." European Economic Review 105 (2018): 83-102. Link
- Angelov, Nikolay, Per Johansson, and Erica Lindahl. "Parenthood and the gender gap in pay." Journal of Labor Economics 34, no. 3 (2016): 545-579. Link
- Moberg, Ylva. Does the gender composition in couples matter for the division of labor after childbirth?. No. 2016: 8. Working Paper, 2016. Link
- Kleven, Henrik, Camille Landais, and Jakob Egholt Søgaard. "Does Biology Drive Child Penalties? Evidence from Biological and Adoptive Families." American Economic Review: Insights 3, no. 2 (2021): 181-209.Link
- Kleven, Henrik, Camille Landais, and Jakob Egholt Søgaard. "Children and Gender Inequality: Evidence from Denmark." American Economic Journal: Applied Economics 11, no. 4 (2019): 181-209.Link
- Lundborg, Petter, Erik Plug, and Astrid Würtz Rasmussen. "Can women have children and a career? IV evidence from IVF treatments." American Economic Review 107, no. 6 (2017): 1611-37. Link
- Andresen, Martin Eckhoff and Emily Nix. "What Causes the Child Penalty? Evidence from Adopting and Same-Sex Couples." Journal of Labor Economics (Forthcoming). Link
- Bütikofer, Aline, Sissel Jensen, and Kjell G. Salvanes. "The Role of Parenthood on the Gender Gap Among Top Earners." European Economic Review 109 (2018): 103-123.Link
- Killewald, Alexandra, and Xiaolin Zhuo. "U.S. Mothers’ Long-Term Employment Patterns." Demography 56, no. 1 (2019): 285-320. Link
- Neumeier, Christian, Todd Sørensen, and Douglas Webber. "The Implicit Costs of Motherhood over the Lifecycle: Cross‐Cohort Evidence from Administrative Longitudinal Data." Southern Economic Journal 84, no. 3 (2018): 716-733. Link
- Lu, Yao, Julia Shu-Huah Wang, and Wen-Jui Han. "Women’s short-term employment trajectories following birth: Patterns, determinants, and variations by race/ethnicity and nativity." Demography 54, no. 1 (2017): 93-118. Link
- Yu, Wei-hsin, and Janet Chen-Lan Kuo. "The motherhood wage penalty by work conditions: How do occupational characteristics hinder or empower mothers?." American Sociological Review 82, no. 4 (2017): 744-769. Link
- Byker, Tanya. "The opt-out continuation: Education, work, and motherhood from 1984 to 2012." RSF: The Russell Sage Foundation Journal of the Social Sciences 2, no. 4 (2016): 34-70. Link
- Kleven, Henrik, Camille Landais, Johanna Posch, Andreas Steinhauer, and Josef Zweimüller. "Child penalties across countries: Evidence and explanations." In AEA Papers and Proceedings, vol. 109, pp. 122-26. 2019. Link