Another look at returns to birthweight

Co-benefits from health and health systems to education

This review draws on over 70 studies spanning 2000 to 2023 to analyze the causal effect of health on educational outcomes. Health and health system interventions during the prenatal, infant, and childhood period impact longer-run educational attainment and performance. The magnitude of these effects is both statistically and economically significant, comparable in size to impacts on educational outcomes of interventions found in the literature. These impacts of health and health system interventions differ across gender and socioeconomic status, illustrating how health and health systems can exacerbate or mitigate educational inequalities. By showing the intertwined nature of health and education, this review highlights the importance of a comprehensive approach in policy-making that aligns with the Sustainable Development Goals.

Unequal before death: The effect of paternal education on children's old-age mortality in the United States

A growing body of research documents the relevance of parental education as a marker of family socio-economic status for children's later-life health outcomes. A strand of this literature evaluates how the early-life environment shapes mortality outcomes during infancy and childhood. However, the evidence on mortality during the life course and old age is limited. This paper contributes to the literature by analysing the association between paternal education and children's old-age mortality. We use data from Social Security Administration death records over the years 1988-2005 linked to the United States 1940 Census. Applying a family(cousin)- fixed-effects model to account for shared environment, childhood exposures, and common endowments that may confound the long-term links, we find that having a father with a college or high-school education, compared with elementary/no education, is associated with a 4.6- or 2.6-month-higher age at death, respectively, for the child, conditional on them surviving to age 47.

Dust to Feed, Dust to Gray: The Effect of in Utero Exposure to the Dust Bowl on Old-Age Longevity

Intensive agriculture and deep plowing caused topsoil erosion and dust storms during the 1930s, affecting agricultural income and land values for years. Given the growing literature on the relevance of in utero and early-life exposures, it is surprising that studies focusing on links between the Dust Bowl and later-life health have produced inconclusive and mixed results. We reevaluate this literature and study the long-term effects of in utero and early-life exposure to topsoil erosion caused by the 1930s Dust Bowl on old-age longevity. Specifically, using Social Security Administration death records linked with the full-count 1940 census, we conduct event studies with difference-in-differences designs to compare the longevity of individuals in high- versus low-topsoil-erosion counties before versus after 1930. We find intent-to-treat reductions in longevity of approximately 0.85 months for those born in high-erosion counties after 1930. We show that these effects are not an artifact of preexisting trends in longevity. Additional analyses suggest that the effects are more pronounced among children raised in farm households, females, and those whose mothers had lower education. We also provide suggestive evidence that reductions in adulthood income are a likely mechanism for the effects we document.

The Siren Song of Cicadas: Early-Life Pesticide Exposure and Later-Life Male Mortality

This paper studies the long-term effects of in-utero and early-life exposure to pesticide use on adulthood and old-age longevity. We use the cyclical emergence of cicadas in the eastern half of the United States as a shock that raises the pesticide use among tree crop growing farmlands. We implement a difference-in-difference framework and employ Social Security Administration death records over the years 1975-2005 linked to the complete count 1940 census. We find that males born in top-quartile tree-crop counties and exposed to a cicada event during fetal development and early-life live roughly 2.2 months shorted lives; those with direct farm exposure face a reduction of nearly a year. We provide empirical evidence to examine mortality selection before adulthood, endogenous fertility, and differential data linkage rates. Additional analyses suggests that reductions in education and income during adulthood are potential mechanisms of impact. Our findings add to our understanding of the relevance of early-life insults for old-age health and mortality.

Long-Term Health Benefits of Occupational Licensing: Evidence from Midwifery Laws

During the late 19th and early 20th century, several states mandated midwifery licensing requirements to improve midwives' knowledge, education, and quality. Previous studies point to the health benefits of midwifery quality improvements for maternal and infant health outcomes. This paper exploits the staggered adoption of midwifery laws across states using event-study and difference-in-difference frameworks. We use the universe of death records in the US over the years 1979-2020 and find that exposure to a midwifery licensing law at birth is associated with a 2.5 percent reduction in cumulative mortality rates and an increase of 0.6 months in longevity during adulthood and old age. The effects are concentrated on deaths due to infectious diseases, neoplasm diseases, and suicide mortality. We also show that the impacts are confined among blacks and are slightly larger among males. Additional analyses using alternative data sources suggest small but significant increases in educational attainments, income, measures of socioeconomic status, employment, and measures of height as potential mechanism channels. We provide a discussion on the economic magnitude and policy implication of the results.

Breathing in the future: prenatal exposure to air pollution and infants' health outcomes in the USA

OBJECTIVES

This study aimed to investigate the impact of air pollution on birth outcomes in the USA over several decades.

STUDY DESIGN

Approximately 70 million birth records were assessed for the years 1980-2020. This study focussed on seven measures of birth outcomes, including birth weight, low birth weight, very low birth weight, full-term birth weight, foetal growth, gestational age and very premature birth.

METHODS

An instrumental variable identification strategy was used that exploited within county-month and within month-year of birth variations in exposure to precipitation-induced changes in air pollution.

RESULTS

Air pollution was found to have negative and large effects on a wide range of birth outcomes. The study findings suggest that a one-standard-deviation increase in ozone was associated with a 6.4% and 12.8% increase (from the mean) in the proportion of low birth weight and very preterm birth infants, respectively. Further analyses suggest that these effects were heterogeneous across trimesters of pregnancy and reveal larger impacts during the second and third trimesters.

CONCLUSIONS

The results suggest that the ordinary least square estimates of previous studies considerably underestimate the true effects of pollution on birth outcomes. Policies that aim to improve the health capital of future generations should allocate more resources and initiatives to improving environmental air quality.

Long-run intergenerational health benefits of women empowerment: Evidence from suffrage movements in the US

An ongoing body of research documents that women empowerment is associated with improved outcomes for children. However, little is known about the long-run effects on health outcomes. This paper adds to this literature and studies the association between maternal exposure to suffrage reforms and children's old-age longevity. We utilize changes in suffrage laws across US states and over time as a source of incentivizing maternal investment in children's health and education. Using the universe of death records in the US over the years 1979-2020 and implementing a difference-in-difference econometric framework, we find that cohorts exposed to suffrage throughout their childhood live 0.6 years longer than unexposed cohorts. Furthermore, we show that these effects are not driven by preexisting trends in longevity, endogenous migration, selective fertility, and changes in the demographic composition of the sample. Additional analysis reveals that improvements in education and income are candidate mechanisms. Moreover, we find substantial improvements in early-adulthood socioeconomic standing, height, and height-for-age outcomes due to childhood exposure to suffrage movements. A series of state-level analyses suggest reductions in infant and child mortality following suffrage law change. We also find evidence that counties in states that passed the law experienced new openings of County Health Departments and increases in physicians per capita.

Mental health and labor supply: Evidence from Canada

This study investigates the relationship between mental health and employment using an instrumental variable approach with the 2012 Canadian Community Health Survey-Mental Health. Using a family member's mental health problem(s) as an instrument for poor mental health, the estimates reveal that poor mental health significantly reduces employment outcomes. These findings are robust to various specifications, such as an alternative instrument and a relaxation of the exclusion restriction assumption. In addition, the relationship is driven mainly by men and younger workers. Moreover, the findings suggest that the relationship is mediated by a decline in cognitive abilities, such as difficulties in concentration and motivation, and social relations with acquaintances and friends. Finally, the estimates show that this phenomenon is contagious: poor mental health has a significant spillover effect on coworkers' mental health in workplaces. This study demonstrates the importance of mental health illness in Canada and other developed countries.

The infant health effects of starting universal child benefits in pregnancy: Evidence from England and Wales

Child benefits are typically paid from birth. This paper asks whether starting universal child benefits in pregnancy leads to improvements in infant health. Leveraging administrative birth registry and hospital microdata from England and Wales, I study the effects of the Health in Pregnancy Grant, a universal conditional cash transfer equivalent to three months of child benefit (190 GBP) as a lump sum to pregnant mothers from 2009 to 2011. I exploit quasi-experimental variation in eligibility with a regression discontinuity design in the date of birth of the baby. I find that the policy increased birth weight by 8-12 grams on average, reduced low birth weight (<2500 g) by 3-6 percent and decreased prematurity by 9-11 percent. Younger mothers, particularly those living in deprived areas, benefit the most. I present evidence that the mechanisms are unlikely to be antenatal care, nutrition or smoking, with reductions in stress remaining a possible explanation.

Sibling rivalry between twins in utero and childhood: Evidence from birthweight and survival of 95 919 twin pairs in 72 low- and middle-income countries

BACKGROUND

This study explores the magnitude and timing of sex and gender disparities in child development by describing differences in health outcomes for male and female siblings, comparing twins to control for all aspects of life circumstances other than sex and gender.

METHODS

We construct a repeat cross-sectional dataset of 191 838 twins among 1.7 million births recorded in 214 nationally representative household surveys for 72 countries between 1990 and 2016. To test for biological or social mechanisms that might favor the health of male or female infants, we describe differences in birthweights, attained heights, weights, and survival to distinguish gestational health from care practices after each child is born.

RESULTS

We find that male fetuses grow at the expense of their co-twin, significantly reducing their sibling's birthweight and survival probabilities, but only if the other fetus is male. Female fetuses are born significantly heavier when they share the uterus with a male co-twin and have no significant difference in survival probability whether they happen to draw a male or a female co-twin. These findings demonstrate that sex-specific sibling rivalry and male frailty begin in utero, prior to gender bias after birth that typically favors male children.

CONCLUSIONS

Sex differences in child health may have competing effects with gender bias that occurs during childhood. Worse health outcomes for males with a male co-twin could be linked to hormone levels or male frailty, and could lead to underestimates of the effect sizes of later gender bias against girls. Gender bias favoring surviving male children may explain the lack of differences in height and weight observed for twins with either male or female co-twins.

Social insurance programs and later-life mortality: Evidence from new deal relief spending

A growing body of research explores the long-run effects of social programs and welfare spending. However, evidence linking welfare support in early life with longevity is limited. We add to this literature by evaluating the effect of in-utero and early-life exposure to the largest increases in welfare spending in the US history under the New Deal programs. Using Social Security Administration death records linked with the 1940-census and spending data for 115 major cities, we show that the spending is correlated with improvements in old-age longevity. A treatment-on-treated calculation focused on a period when spending rose by approximately 1900 percent finds that a 100 percent rise in municipal spending in the year of birth is associated with roughly 3.5 months higher longevity. We show that these effects are not driven by endogenous selection of births, selective fertility, endogenous migration, and sample selection caused by endogenous data linking. Additional analysis suggests that rises in education and socioeconomic status are likely channels of impact.

Maternal human capital and infants' health outcomes: Evidence from minimum dropout age policies in the US

The purpose of this cross-sectional study is to examine the causal relationship of maternal education and infants' health outcomes. Using birth certificate data over the years 1970–2004 and exploiting the space-time variation in Minimum Dropout Age laws to solve the endogeneity of education, we find a sizeable effect of mothers' education on their birth outcomes. An additional year of maternal education is associated with a reduction in incidences of low birth weight and preterm birth by 15.2 and 12.7 percent, respectively. The estimates are robust across various specifications and even when allowing mothers’ cohort-of-birth to vary across regions. The results suggest that the candidate mechanisms of impact include improvements in timing, quantity, and quality of prenatal care, lower negative health behavior during pregnancy such as smoking and drinking, and higher spousal education.

•

We provide causal evidence on the effect of mothers' education on birth outcomes.

•

We use Minimum Dropout Age policies as the instrument.

•

Mother education has significant impact on infants' birth outcomes.

•

Candidate mechanisms include improvements in timing, quantity, and quality of prenatal care.

Intergenerational health effects of Medicaid

This paper investigates the effects of the introduction of Medicaid during the 1960s on next generations' birth outcomes. A federal mandate that all states must widen the coverage to all cash welfare recipients generated cross-state variations in Medicaid eligibility, specifically among nonwhites who largely overrepresented the target population. I implement a reduced-form difference-in-differences strategy that compares the birth outcomes of mothers born in states with higher cash welfare recipiency versus low welfare recipiency and different years relative to the Medicaid implementation year. Using Natality data (1970-2004), I find that Medicaid significantly improves birth outcomes. The effects are considerably larger among nonwhites, specifically blacks. The effects do not appear to be driven by preexisting trends in birth outcomes, preexisting trends in households' socioeconomic characteristics, changes in other welfare expenditures, and selective fertility. A back-of-an-envelope calculation points to a minimum of 3.9% social externality of Medicaid through income rises due to next generations' improvements in birth outcomes.

The role of health at birth and parental investment in early child development: evidence from the French ELFE cohort

This paper combines a theoretical and an empirical approach to address how health at birth affects child development. Using a simple theoretical model in which parents invest in their children, we identify the mechanisms through which better health at birth can improve child development. We also emphasise how parental socioeconomic status can shape the effects of health at birth. We perform an empirical analysis on a French cohort of children born in 2011, using a unique dataset ELFE. We identify the effect of birth weight and gestational age on child development at 1 year. The results indicate that only gestational age positively affects early development. We find no empirical evidence for the existence of a severity effect, according to which the adverse effects of poor health at birth are higher for children in low-income families or with poorly educated mothers.

Birth weight and adult income: An examination of mediation through adult height and body mass

This paper examines the causal links between early human endowments and socioeconomic outcomes in adulthood. We use a genotyped longitudinal survey (Cardiovascular Risk in Young Finns Study) that is linked to the administrative registers of Statistics Finland. We focus on the effect of birth weight on income via two anthropometric mediators: body mass index (BMI) and height in adulthood. We find that (i) the genetic instruments for birth weight, adult height, and adult BMI are statistically powerful; (ii) there is a robust total effect of birth weight on income for men but not for women; (iii) the total effect of birth weight on income for men is partly mediated via height but not via BMI; and (iv) the share of the total effect mediated via height is substantial, of approximately 56%.

The impact of mental health parity laws on birth outcomes

Prior studies have found that poor mental health during pregnancy is associated with poor birth outcomes, but little is known about the ability of mental health care access and treatment to counteract these effects. I use a difference-in-differences strategy exploiting the staggered enactment of state mental health parity laws in 25 states from 1995 to 2002 to identify the impact of mental health care access on the probability of an adverse birth outcome. These state mental health parity laws are insurance mandates requiring coverage of mental health care be equivalent to physical health care. Using birth records, I find that, among the group of mothers most likely to have private insurance, introduction of a mental health parity law in a state decreased the probability of an adverse birth outcome. Furthermore, I find that the parity laws decreased the likelihood that a pregnant woman hospitalized for delivery would receive a mental illness diagnosis.