Challenging Parents
The Effect of Maternal Labor Supply on Children: Evidence from Bunching
Carolina Caetano et al.
Journal of Labor Economics, forthcoming
Abstract:
We study the effect of maternal labor supply in the first three years of life on early childhood cognitive skills. We pay particular attention to heterogeneous effects by the skill of the mother, by the intensity of her labor supply, and by her pre-birth wages. We correct for selection using a control function approach which uses the fact that many mothers are bunched at zero working hours -- skill variation in the children of these bunched mothers is informative about the effect of unobservables on skills. We find that maternal labor supply typically has a significant, negative effect on children’s early cognitive skills, with more negative effects for higher-skill mothers. By contrast, we do not find significant heterogeneity by the pre-birth wage rate of the mother. These results suggest that even highly paid, highly skilled mothers are not able to use income to fully offset the negative short-run effects of their working hours on their children’s skills.
The Impact of Unconditional Cash Transfers on Parenting and Children
Patrick Krause et al.
NBER Working Paper, July 2025
Abstract:
This paper examines the impact of a large, randomized cash transfer on parental behaviors, investment in children, children's social, behavioral, and educational outcomes, and pregnancy and childbearing. We find that parents who were randomly selected to receive a $1,000 per month unconditional cash transfer for three years spent more on their children each month and reported better parenting behaviors (such as supervising their children more closely) compared to those randomized to receive $50 per month over the same period. However, possibly due to this closer monitoring, parents in the treatment group also reported that their child was experiencing more developmental difficulties and stress. Parents with the lowest incomes at baseline experienced the largest improvements in parenting; among these parents, the transfer also increased the use and quality of non-parental child care. The transfer did not have a meaningful effect on most educational outcomes measured in school administrative records, nor did it affect characteristics of the home environment, child food security, exposure to homelessness, or parental satisfaction. Although treated families were more likely to move, we did not detect changes in most measures of neighborhood quality, though proximity to child-focused amenities such as daycares appeared to increase in the treatment group relative to the control group. The transfer did not affect childbearing, pregnancy, or outcomes related to contraception. While the transfer reduced parents' stress and mental distress in the first year of the program, these effects were short-lived and dissipated by the second year of the transfer, analogous to what was documented previously in the full population of participants.
The Causal Effects of Education on Age at Marriage and Marital Fertility
Neil Cummins
European Review of Economic History, August 2025, Pages 273-320
Abstract:
The negative association of education and fertility, over time and between countries, is a central stylized fact of social science. Yet we have scant evidence on whether this is, or is not, causal. Using the universe of vital registration index data from England, 1912 to 2007, I first show that it is possible, using unique names, to construct a demographically and socioeconomically representative sample of 1.5 million women. Historical record linkage of women is typically not attempted but is possible here because of the unique characteristics of English civil registration. I then exploit the natural experiment of sharp discontinuities in who was affected by compulsory schooling law changes in 1947 and in 1972, which exogenously and effectively raised the minimum school leaving age. A Regression Discontinuity design, executed on the individual data, identifies the causal effect of education on age at marriage and fertility. Education may have raised age at marriage in 1972. However one extra year of education at 15 or 16 has a zero causal effect on marital fertility.
Is sex at birth a biological coin toss? Insights from a longitudinal and GWAS analysis
Siwen Wang et al.
Science Advances, July 2025
Abstract:
Some families consistently have offspring of only one sex, raising questions about whether sex at birth is truly random. This study investigated whether offspring sex follows a simple binomial distribution within families and identified maternal factors associated with unisexual sibships. We analyzed 58,007 US women with two or more singleton live births (146,064 pregnancies, 1956–2015). Offspring sex followed a beta-binomial rather than a simple binomial distribution, indicating that each family may have a unique probability of male or female births, akin to a weighted coin toss. Deviations from simple binomial distribution were more pronounced when we excluded each woman’s last birth to reduce the influence of sex-based stopping behavior. After excluding the last birth, older maternal age at first birth was associated with higher odds of having offspring of only one sex. A genome-wide association study identified maternal SNPs linked to having female-only (NSUN6) and male-only (TSHZ1) offspring. Our findings suggest maternal factors influence offspring sex distributions.
Parent-of-origin effects on complex traits in up to 236,781 individuals
Robin Hofmeister et al.
Nature, forthcoming
Abstract:
Parent-of-origin effects (POEs) occur when the effect of a genetic variant depends on its parental origin. Traditionally linked to genomic imprinting, POEs are believed to occur due to parental conflict over resource allocation to offspring, resulting in opposing parental influences. Despite their importance, POEs remain underexplored in complex traits, owing to the lack of parental genomes. Here we present an approach to infer the parent of origin of alleles without parental genomes, leveraging interchromosomal phasing, mitochondrial and X chromosome data, and sex-specific crossover in siblings. Applied to the UK Biobank, this enabled parent-of-origin inference for up to 109,385 individuals. Genome-wide association study scans for 59 complex traits and over 14,000 protein quantitative trait loci contrasting maternal and paternal effects identified over 30 POEs and confirmed more than 50% of known associations. More than one third of these showed opposite parental influences, especially for traits related to growth (for example, IGF1 and height) and metabolism (for example, type 2 diabetes and triglyceride levels). Replication in up to 85,050 individuals from the Estonian Biobank and 42,346 offspring from the Norwegian Mother, Father and Child Cohort Study (MoBa) validated 87% of testable associations. Overall, our findings highlight the contribution of POEs to complex traits and support the parental conflict hypothesis, providing compelling evidence for this understudied evolutionary phenomenon.