Laura Bliss is a staff writer at CityLab, covering transportation and technology. She also authors MapLab, a biweekly newsletter about maps (subscribe here). Her work has appeared in the New York Times, The Atlantic, Los Angeles magazine, and beyond.
For every dollar that state minimum wages go up, birth outcomes improve, two new studies find.
In the U.S., the debate around the minimum wage does not lack controversy, but it does lack up-to-date research. Academic studies on the effects of raising hourly pay—especially to $15, which has become something of a magic number for progressive cities and states—have not kept pace with the whirlwind movement. And relatively little research has focused on the non-economic impacts of such significant wage bumps: for example, how they affect the health of infants.
This is no arbitrary question. Women make up the majority of minimum-wage workers. In the U.S., income level has a pronounced, positive link to birth weight and infant mortality. Low birth weights are associated with myriad long-term poor outcomes for children, including respiratory and cardiovascular sickness, cognitive and developmental issues, and lower educational attainment. These effects have led some economists to characterize the health trajectories for some kids born to poor parents as being “unequal at birth.”
So when hourly pay gets bumped up, what benefits (if any) extend to the tiniest citizens? Two recent studies—a working paper in NBER and research published in the American Journal of Public Health—evaluate that question.
The NBER study examines how state-level minimum wages affect birth weight, length of gestation, and fetal development among births in the U.S. between 1989 and 2012, focusing on a sample of women with low educational status. The AJPH researchers focused on a similar time frame—1980 to 2011—and tracked the effects of more than 200 changes to state minimum wages on rates of low birth weight and infant mortality.
Both studies controlled for other factors that can influence infant health, such as whether the mother smoked, how often she received medical care, and whether the family received Medicaid benefits or earned-income tax credits. They also accounted for potential negative effects of increased minimum wages, such as job losses.
The findings? Increases in minimum wage are associated with significant net positive effects for newborn health, the two papers concluded. The authors of the NBER study write:
… An increase in the minimum wage is associated with a significant increase in birth weight: a $1 increase in the minimum wage increases birth weight by about 11 grams, which would imply an 85 grams increase with a $7.75-dollar increase in the minimum wage from the current federal level of $7.25 to $15. A $1 increase in minimum wage is also associated with a 0.2 percentage point, or 2%, decrease in the probability of low-birth weight.
The AJPH researchers found a “consistent pattern” of improvements in newborn health—with very, very similar results to the NBER paper. They found that a $1 increase in the state wage above the federal minimum was associated with a 1 to 2 percent decrease in low-weight births, and a 4 percent decrease in post-neonatal deaths. Kim Krisberg for Science Blogs reports on the AJPH study:
That means if all states had bumped up their minimum wages by $1 in 2014, it may have prevented nearly 2,800 low birth weight births and more than 500 infant deaths in that year alone, the study found.
That’s a considerable boost to the number of children making it past their first birthdays, and to those with a better shot at long-term health and educational success. To put these implications into tighter focus, another study published in April calculated that if New York City had had a $15 minimum wage between 2008 and 2012, it could have “averted 2,800 to 5,500 premature deaths,” mostly in low-income communities of color.
What could be driving these outcomes? The NBER authors surmise:
Greater income may increase medical care such as prenatal care services, particularly among those who are in low-paying jobs, likely to be affected by the minimum wage and likely to be without health insurance. Increased income may increase financial security, which may reduce maternal stress, a factor linked to fetal growth[.]
Seattle, San Francisco, Los Angeles, New York City, and Washington, D.C., now have $15 minimum wage laws on their books, and New York and California recently passed statewide measures to phase in that pay rate. But the figure still remains controversial among economists. It is roughly double the current federal minimum wage, and the size of the wage hikes that many of these cities and states have made are unprecedented. While proponents argue that minimum wage hikes temper economic inequality, skeptics wonder if it may have adverse effects on those very workers, forcing layoffs, price increases on goods and services, or both.
A $15 minimum wage is not necessarily poverty’s Kryptonite. But these new studies suggest that increases to hourly wages are a boon to newborn health. In turn, healthier babies can offer society a lifetime of dividends.