Kevin Lewis

October 28, 2018

Did California Paid Family Leave Impact Infant Health?
Ariel Marek Pihl & Gaetano Basso
Journal of Policy Analysis and Management, forthcoming


The effects of paid parental leave policies on infant health have yet to be established. In this paper we investigate these effects by exploiting the introduction of California Paid Family Leave (PFL), the first program in the U.S. that specifically provides working parents with paid time off for bonding with a newborn. We measure health using the full census of infant hospitalizations in California and a set of control states, and implement a differences‐in‐differences approach. Our results suggest a decline in infant admissions, which is concentrated among those causes that are potentially affected by closer childcare (and to a lesser extent breastfeeding). Other admissions that are unlikely to be affected by parental leave do not exhibit the same pattern.

Intensive Parenting: Fertility and Breastfeeding Duration in the United States
Vida Maralani & Samuel Stabler
Demography, October 2018, Pages 1681–1704


Using 30 years of longitudinal data from a nationally representative cohort of women, we study the association between breastfeeding duration and completed fertility, fertility expectations, and birth spacing. We find that women who breastfeed their first child for five months or longer are a distinct group. They have more children overall and higher odds of having three or more children rather than two, compared with women who breastfeed for shorter durations or not at all. Expected fertility is associated with initiating breastfeeding but not with how long mothers breastfeed. Thus, women who breastfeed longer do not differ significantly from other breastfeeding women in their early fertility expectations. Rather, across the life course, these women achieve and even exceed their earlier fertility expectations. Women who breastfeed for shorter durations (1–21 weeks) are more likely to fall short of their expected fertility than to achieve or exceed their expectations, and they are significantly less likely than women who breastfeed for longer durations (≥22 weeks) to exceed their expected fertility. In contrast, women who breastfeed longer are as likely to exceed as to achieve their earlier expectations, and the difference between their probability of falling short versus exceeding their fertility expectations is relatively small and at the boundary of statistical significance (p = .096). These differences in fertility are not explained by differences in personal and family resources, including family income or labor market attachment. Our findings suggest that breastfeeding duration may serve as a proxy for identifying a distinct approach to parenting. Women who breastfeed longer have reproductive patterns quite different than their socioeconomic position would predict. They both have more children and invest more time in those children.

Childless Expectations and Childlessness Over the Life Course
Anna Rybińska & Philip Morgan
Social Forces, forthcoming


Using nineteen panels of the 1979 National Longitudinal Survey of Youth (NLSY-79), we construct life-lines characterizing women’s childless expectations and fertility behavior. One-quarter of women in the NLSY-79 cohort ever reported an expectation for childlessness but only 14.8 percent of women remain childless. Childless women follow two predominant life course paths: (1) repeated postponement of childbearing and the subsequent adoption of a childless expectation at older ages or (2) indecision about parenthood signaled through vacillating reports of childless expectations across various ages. We also find that more than one in ten women became a mother after considering childlessness: an understudied group in research on childlessness and childbearing preferences. These findings reaffirm that it is problematic to assign expected and unexpected childlessness labels to the reproductive experience of childless women. In addition, despite their variability over time, childless expectations strongly predict permanent childlessness, regardless of the age when respondents offer them. Longitudinal logistic regression analysis of these childless expectations indicates a strong effect of childbearing postponement among the increasingly selective group of childless women. However, net of this postponement, few variables commonly associated with childlessness are associated with reports of a childless expectation. We thus conclude that the effects of socio-demographic and situational factors on childless expectations are channeled predominantly through repeated childbearing postponement.

Parental influence and private school enrollment among children in blended families
Kevin Thomas
Social Science Research, forthcoming


In this study, the analysis examines how variations in parental influence shape private school enrollment among children in blended families. The results show that investment in private schooling for children is higher in families with notable parental income differences than in families with parents with similar incomes. Net of these factors, however, parents in nuclear families are more likely to invest in the provision of private schooling compared to parents in blended families. In blended families, the analysis underscores the significance of two dimensions of biological relatedness for developing nuanced understandings of inequalities among children. On average, parents in these families make greater investments in the provision of private schooling for their shared biological children than for their stepchildren, broadly defined. Disaggregating stepchildren based on their own biological ties with parents, however, reveals substantially higher investments in private schooling for stepchildren biologically related to household heads than for either shared biological children or other stepchildren. The advantage of stepchildren with biological ties to household heads is more pronounced in families where household heads earn more than their spouses. However, it remains statistically significant even when the opposite is true.

Enhancing the language development of toddlers in foster care by promoting foster parents’ sensitivity: Results from a randomized controlled trial
Kenneth Lee Raby et al.
Developmental Science, forthcoming


Young children in foster care are at increased risk for problematic language development, making early intervention a critical tool in enhancing these children's foundational language abilities. This study examined the efficacy of an early preventative intervention, Attachment and Biobehavioral Catch‐up for Toddlers (ABC‐T), in improving the receptive vocabulary abilities of toddlers placed in foster care. All the children had been removed from their biological parents’ care and placed into foster care. When children were between 24 and 36 months old, foster parents were contacted by research staff and consented to participate. Parents were randomly assigned using a random number generator to receive either ABC‐T (n = 45), which aimed to promote sensitive parenting for children who have experienced early adversity, or a control intervention (n = 43). Foster children's receptive vocabulary skills were assessed post‐intervention using the Peabody Picture Vocabulary Test, Third Edition, when children were between 36 and 60 months old. Children whose foster parents received ABC‐T demonstrated more advanced receptive vocabulary abilities than children whose foster parents received the control intervention. The positive effect of ABC‐T on foster children's receptive vocabulary was mediated by increases in foster parents’ sensitivity during parent–child interactions.

Sibling Achievement, Sibling Gender, and Beliefs about Parental Investment: Evidence from a National Survey Experiment
Natasha Quadlin
Social Forces, forthcoming


When siblings have different characteristics — such as different achievement or different gender — how should parents invest in their education? Although many studies have examined issues of parental investment using behavioral data, this research is often hindered by methodological constraints, including endogeneity and an inability to isolate the effects of predictor variables. This article takes an alternative approach by using data from an original, nationally representative survey experiment (N = 3,239). I assess how Americans believe parents should divide educational resources between siblings with different achievement and gender. In doing so, this article is the first to examine normative beliefs surrounding relative achievement, gender, and parental investment in siblings’ education. When achievement is the only difference between siblings, respondents believe that lower achievers should receive more hands-on instructional resources and parental school involvement, and higher achievers should receive more resources that enhance cultural capital and support college enrollment. This pattern maps onto the way respondents divide resources between boys and girls. When gender is the only difference between siblings, respondents believe that boys should receive more instructional resources and parental school involvement, while girls should receive more cultural and college resources. When achievement and gender both differ, however, the effect of relative achievement typically crowds out the effect of gender, suggesting that respondents’ evaluations of achievement are more persistent than their evaluations of gender. Implications for research on parental involvement in education are discussed.

Variation in the Heritability of Child Body Mass Index by Obesogenic Home Environment
Stephanie Schrempft et al.
JAMA Pediatrics, forthcoming

Design, Setting, and Participants: This study was a gene-environment interaction twin study that used cross-sectional data from 925 families (1850 twins) in the Gemini cohort (a population-based prospective cohort of twins born in England and Wales between March and December 2007). Data were analyzed from July to October 2013 and in June 2018.

Exposures: Parents completed the Home Environment Interview, a comprehensive measure of the obesogenic home environment in early childhood. Three standardized composite scores were created to capture food, physical activity, and media-related influences in the home; these were summed to create an overall obesogenic risk score. The 4 composite scores were split on the mean, reflecting higher-risk and lower-risk home environments.

Results: Among 1850 twins (915 [49.5%] male and 935 [50.5%] female; mean [SD] age, 4.1 [0.4] years), the heritability of BMI SD score was significantly higher among children living in overall higher-risk home environments (86%; 95% CI, 68%-89%) compared with those living in overall lower-risk home environments (39%; 95% CI, 21%-57%). The findings were similar when examining the heritability of BMI in the separate food and physical activity environment domains.

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