by Maya Rossin-Slater
Department of Economics, UC Santa Barbara

Despite being among the wealthiest countries in the world, the United States fares relatively poorly by standard indicators of early childhood health. For example, according to the U.S. Centers for Disease Control and Prevention, the U.S. infant mortality rate was ranked 32nd among the 34 countries of the Organization for Economic Cooperation and Development (OECD) in 2010¹. Similarly, the World Health Organization reports that the U.S. preterm birth rate (defined as birth at less than 37 weeks of gestation) ranks 130th out of the 184 countries with available data.²

An important driver of the U.S. infant health disadvantage is its higher cross-group inequality relative to similarly wealthy countries. In particular, there are large disparities in infant health by race and socio-economic status. For example, relative to non-Hispanic white mothers, African American mothers are 90 percent more likely to have a low birth weight birth and 70 percent more likely to have a preterm birth. Unmarried mothers and those with low education levels have higher rates of adverse birth outcomes relative to their married and more educated counterparts.

The U.S. disadvantage in infant health is especially relevant in light of a growing body of research documenting lasting impacts of early-life conditions on outcomes throughout the life cycle. The link between early-life health and adult well-being was first formalized by David J. Barker, a British physician and epidemiologist, who coined the phrase “the fetal origins hypothesis”. Barker argued that adverse in-utero conditions can “program” a fetus to have metabolic characteristics that are associated with future disease. Economist James Heckman and his co-authors have further argued that there are important dynamic complementarities between investments in children at different stages of development. This means that initial health endowments raise the productivity of investments at later ages, making it increasingly difficult to overcome initial differences in health.

There are a large number of studies documenting a relationship between different types of in utero and early childhood shocks and adult outcomes. For example, several epidemiological studies have compared cohorts who were in utero during the 1944 Dutch famine to cohorts who were born just before or after, showing that those exposed to the famine in utero had higher rates of obesity, cardiovascular disease, and mental illness at age 70 (Stein et al., 2007; Hoek et al., 1998).

Economists have looked at the effects of exposure to other types of events. Doug Almond’s seminal 2006 study shows that cohorts exposed to the 1918 U.S. influenza epidemic in utero had lower educational attainment, adult earnings, and were more likely to receive disability and welfare benefits relative to cohorts born in surrounding years (Almond, 2006). Other studies have demonstrated that increased exposure to air pollution in early life reduces high school test scores and earnings at age 30 (Sanders, 2012; Isen et al., Forthcoming). Exposure to lead and radiation in early childhood similarly negatively impacts adult socio-economic status (Reyes, 2007; Almond et al., 2009; Black et al., 2013). Finally, income in early life matters as well. A recent study shows that having access to the Food Stamps program at birth improves health and measures of economic self-sufficiency in adulthood (Hoynes et al., 2012).

Other research has shown that differences in early-life health measures translate into differences in adult outcomes. Birth weight is commonly seen as a summary measure of health at birth, and one study comparing birth weight differences between twins showed that a 10 percent increase in birth weight increases adult full-time earnings by one percent (Black et al., 2007).

This body of research suggests that the U.S. early-life health disadvantage may have profound consequences not only for population wellbeing, but also for economic growth and competitiveness in a global economy. Policies that target early-life conditions, especially among vulnerable populations, could help reverse this trend as well as ameliorate intergenerational persistence of economic disadvantage and reduce inequality. Here, I discuss three of the most prominent and effective U.S. policies in this arena.

First, the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) serves low-income pregnant women and children through age five, and provides benefits that can be used to buy nutritious food. Recent research shows that access to WIC during pregnancy decreases the probability of a low birth weight birth by 8-14 percent (Rossin-Slater, 2013).

Second, family leave policies provide time off from work so that new mothers can prepare for childbirth and stay home to care for their newborns. These policies are important because most low-wage women do not have access to any employer-provided paid time off from work. Although the U.S. does not have a national paid family leave policy, the 1993 Family and Medical Leave Act (FMLA) grants twelve weeks of unpaid job-protected leave to eligible workers. Research shows that the introduction of FMLA led to improvements in infant health among children of highly educated and married women, who could afford to take unpaid time off work (Rossin, 2011). Paid family leave, however, can improve early-life health among disadvantaged populations. One study shows that paid maternity leave benefits offered through the Temporary Disability Insurance (TDI) system in five states since 1978 reduced the incidence of low birth weight and preterm births among minority and unmarried mothers (Stearns, Forthcoming). California’s 2004 paid family leave program has been shown to increase breastfeeding rates among unmarried and minority mothers with low education levels (Huang and Yang, 2014).

Finally, home visitation programs are designed to provide low-income parents with education about parenting, health, and resource availability through regular home visits by trained staff early in the child’s life. One particularly successful program is the Nurse Home Visiting Partnership (NHVP), which targets at-risk mothers and focuses on teaching them how to assess infant health and create safe households. Randomized evaluations of the NHVP indicate that participating mothers are 63 percent more likely to breastfeed, and their young children experience fewer health problems. The program also has lasting effects on later cognitive ability: children exposed to NHVP in infancy score 26 percent higher on achievement tests at age nine than unexposed children. The success of NHVP is attributed to its highly-trained staff and its targeted design; larger-scale interventions with less skilled home visitors have been shown to be less effective (Olds, 2006).

In sum, mounting evidence points to the lasting consequences of early-life health on adult well-being. Reducing inequalities in infant health may therefore be an important avenue for addressing broader economic inequality. Policies that have been shown to improve early-life health among disadvantaged children include WIC, paid family leave, and nurse home visiting programs.

Notes

1. ^ See: Wanda Barfield et al. CDC Grand Rounds: Public Health Approaches to Reducing U.S. Infant Mortality (Atlanta: U.S. Centers for Disease Control and Prevention, 2013), 62(31): 625-628. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6231a3.htm
2. ^ See: Christopher Howson et al. Born Too Soon: The Global Action Report on Preterm Birth. (Geneva: World Health Organization, 2012). http://www.who.int/pmnch/media/news/2012/201204_borntoosoon-execsum-eng.pdf

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