The United States has a surprisingly high infant mortality rate for a wealthy nation. In 2014, 23,000 children died before the age of 1, a figure higher than what’s found in most of Europe, Japan, and Korea. Some argue this is because of our high numbers of preterm births, unplanned pregnancies, and use of infertility treatments. (The latter leads to more twins, which leads to higher rates of preterm births.) Others suspect that our rates have something to do with the fact that we count premature births, including those with a small chance of surviving, as infants in our data. Or that black children, of which there are more in the U.S. compared to Europe, are more likely to die in their first year of life—even when their moms receive quality prenatal care.
Until now, these explanations have been mostly speculative, products of educated guesses rather than rigorous analysis. This is because studies comparing infant mortality rates country-to-country were based on using aggregate data, meaning that the researchers did not take into account the various ways countries define categories and report rates.
In a recently published paper in the American Economic Journal: Economic Policy, authors Alice Chen, Emily Oster, and Heidi Williams relied on microdata, or individual records as opposed to aggregates, to look the difference in infant mortality rates and causes between the United States and Finland, Austria, Belgium, and the United Kingdom. They confirmed that our infant mortality rates are bad, but not for the reasons many thought.
A few assumptions about our infant mortality rate that the paper dispels: It’s not a result of the quality of care a woman receives during pregnancy, nor is it a result of higher rates of twins from infertility treatments. It’s also not because of race; the authors excluded black people from the sample and found that the rate of deaths for babies who die between ages 1 month to 1 year remained the same. Most important, our high rate has nothing to do with preterm births. In fact, the rate of neonatal mortality, or death before 1 month of age, is lower in the United States than the other countries studied. (Some have attributed this to the fact that American doctors are more aggressive in their attempts to keep these babies alive.)
What’s keeping our infant mortality rate so high, then, is the relatively large number of postneonatal deaths, or loss of life between 1 month and 12 months of age, which usually happen at home. Unsurprisingly, the authors found that “disadvantaged groups account for an outsized share of the cross-regional differences in postneonatal mortality rates.” The relatively poor census region of East South Central has a 1-year mortality rate that is twice as high as the wealthier North East. Relatedly, upper-income individuals in Finland, Austria, and the United States experience similar infant mortality rates.
The authors conclude the paper by supporting nurse home visits for new parents, during which they would receive a well check-up for their baby along with advice and support on caregiving. Research shows that these visits, which are far more common in Europe, can lead to a lower rate of SIDS, sudden deaths, and accidents—the primary causes of postneonatal deaths. However, as promising as standardized nurse home visits sound, I can’t see them making much of a change unless they are accompanied by a standardized—and paid—parental leave policy. Teaching parents how to be better caretakers won’t do much good if they can’t afford to stay home to do that caretaking themselves.