For Children
Decoupled? The Persistent Relevance of Marriage for Childbearing in the 2010s United States
Kristen Lagasse Burke
Demography, forthcoming
Abstract:
Prevailing theories of family change and the relevance of marriage in the United States hinge on the steady rise in births to unmarried women that unfolded during the latter half of the twentieth century and into the 2000s. This increase was concentrated among individuals with lower education levels, raising concern about inequality in children's family circumstances. Despite theoretical expectations that this trend would continue, the proportion of births to unmarried women plateaued during the 2010s. By examining trends in union formation and childbearing patterns by union status using data from the 2006‒2023 American Community Survey, this study investigates the ongoing link between marriage and childbearing underlying this plateau. Birth and marriage rates fell throughout the 2010s. However, in a reversal, married women became increasingly likely to have children relative to their unmarried peers, particularly among those with a high school education or less. These findings challenge theories about the changing social meaning of marriage, suggesting that norms regarding marriage remain robust rather than becoming deinstitutionalized. Furthermore, this study highlights how the declining marriage rate has contributed to the ongoing decline in the birth rate in the United States, implying that barriers to marriage may also create barriers to childbearing.
Do Parents Propagate Inequality Among Children? Evidence From Chinese and Swedish Twins
Aiday Sikhova, Sven Oskarsson & Rafael Ahlskog
International Economic Review, forthcoming
Abstract:
Economists have long studied how parental behavior shapes within-family inequality, yet empirical findings remain mixed. Using twins data from China and Sweden, we examine the predominant mechanisms reported in the literature. Parents in both countries invest similarly during childhood. Inter vivos transfers, however, differ: Chinese parents reinforce income inequality, whereas Swedish parents distribute wealth equally; the reinforcing pattern reflects exchange motives. Bequests are divided equally in both countries. Parental education plays a key role: less educated parents reinforce income inequality, whereas more educated parents transfer wealth equally. Cross-country differences in parental education may thus help explain the mixed findings.
Does Employment Shift Mothers' Voting Behavior and Political Identity?
Jacob Bastian
NBER Working Paper, March 2026
Abstract:
While the correlation between working and voting is positive, I provide the first causal evidence that this relationship is negative. Using five decades of Earned Income Tax Credit (EITC) expansions and 1990s welfare reform as instruments for employment, I find that working lowers voter turnout and increases conservatism among lower-income mothers. Voter registration, political knowledge, and civic engagement decline, while preferences for conservative policies rise. Effects are largest for unmarried, younger, and less-educated mothers and are substantially stronger outside metropolitan areas. Notably, political shifts are concentrated among White women despite larger employment gains among non-White women, driven in part by White women entering more conservative coworker environments. Prior exposure to work also matters: women without working mothers experience larger ideological shifts. While recent decades have seen more women voting Democrat, even more women would have voted Democrat if not for decades of pro-work public policy targeting lower-income mothers.
In Utero Selection Echoes Across a Lifetime: Evidence From Historical Utah Populations
Tim Bruckner et al.
American Journal of Human Biology, March 2026
Objectives: Past work in historical demography finds mixed evidence regarding the role of selective cohort mortality in utero in shaping that cohort's older-age mortality. Here we use, for the first time, high-quality individual-level historical data to test whether adults from birth cohorts with a presumed high level of selection in utero show greater than expected older age survival. We examine a frontier population in Utah, born from 1850 to 1920 and followed to 2020, and use the annual cohort sex ratio (M:F) at birth, a marker of cohort selection in utero against males.
Methods: We performed Cox proportional hazards analyses (n = 201 542) to predict the hazard of older-age male mortality (i.e., > 50 years) and used a two-stage correction strategy to control for selective mortality before older age (i.e., before age 50). Analyses also control for strong temporal patterns in cohort survival and individual covariates including month of birth and religious affiliation.
Results: Consistent with our hypothesis, we find that males born to the least selected cohorts -- as indicated by a high sex ratio at birth -- show greater than expected hazard of older-age (i.e., > 50 years) mortality (p < 0.05). Interestingly, our exploration also shows a greater hazard of older-age mortality among females born to high sex ratio cohorts (p < 0.05).
Conserved shifts in sperm small non-coding RNA profiles during mouse and human aging
Junchao Shi et al.
EMBO Journal, 16 February 2026, Pages 1362-1380
Abstract:
Sperm aging impacts male fertility and offspring health, highlighting the need for reliable aging biomarkers to guide reproductive decisions. However, the molecular determinants of sperm fitness during aging remain ill-defined. Here, we profiled sperm small non-coding RNAs (sncRNAs) using PANDORA-seq, which overcomes RNA modification–induced detection bias to capture previously undetectable sncRNA species associated with mouse and human spermatozoa throughout the lifespan. We identified an “aging cliff” in mouse sperm RNA profiles -- a sharp age-specific transition marked by significant shifts in genomic and mitochondrial tRNA-derived small RNAs (tsRNAs) and rRNA-derived small RNAs (rsRNAs). Notably, rsRNAs in mouse sperm heads exhibited a transformative length shift, with longer rsRNAs increasing and shorter ones decreasing with age, suggesting altered biogenesis or processing with age. Remarkably, this sperm head-specific shift in rsRNA length was consistently observed in two independent human aging cohorts. Moreover, transfecting a combination of tsRNAs and rsRNAs resembling the RNA species in aged sperm was able to induce transcriptomic changes in mouse embryonic stem cells, impacting metabolism and neurodegeneration pathways, mirroring the phenotypes observed in offspring fathered by aged sperm. These findings provide novel insights into longitudinal dynamics of sncRNAs during sperm aging, highlighting an rsRNA length shift conserved in mice and humans.