New research shows that reductions in air pollution have intergenerational consequences
When the National Ambient Air Quality Standards were introduced in the United States 50 years ago as part of the 1970 Clean Air Act amendments, concerns about air pollution were largely focused on respiratory health and visible air quality. In the decades since, academics and policymakers alike have learned that the impacts of air pollution are more far-reaching, affecting many dimensions of health, economic productivity, and overall economic and social well-being. We also have learned that disadvantaged communities are disproportionately exposed to pollution along these same dimensions.
This new evidence demonstrates that environmental injustice and economic inequality need to be examined together. This increasing body of evidence on the broadly negative effects of air pollution suggests that differences in environmental quality may play an important role in driving and propagating economic disparities.
Children are especially vulnerable to the effects of air pollution. Growing evidence suggests that exposure to pollution and other environmental risks in early childhood can play a critical role in shaping economic opportunity, with persistent effects on health and well-being. Fortunately, improvements in air quality delivered by the Clean Air Act have been shown to deliver significant benefits to those directly affected, reducing infant mortality and increasing wealth and later-life earnings.
Our new working paper, titled “The Grandkids Aren’t Alright: The Intergenerational Effects of Prenatal Pollution Exposure,” further underscores the value of the Clean Air Act. We find that that it was not only the children of women who benefited from regulatory reductions in exposure to air pollution during pregnancy, but also their grandchildren. The grandchildren of women who were exposed to lower levels of air pollution during pregnancy were more likely to attend college and less likely to drop out of high school 40 years later. A 10 percent reduction in prenatal exposure to particulate matter for individuals born around 1970 is associated with a 3.2 percentage point to 3.8 percentage point increase in the likelihood that their children attend college 40 years later. This corresponds to an 8 percent increase in attendance, compared with the average college attendance rate.
To measure these outcomes, we use administrative and survey data from the U.S. Census Bureau, which allows us to construct more than 150 million parent-child links. We then take advantage of the structure of the 1970 Clean Air Act amendments as a natural experiment. These amendments designated counties that exceeded the newly instated National Ambient Air Quality Standards as “nonattainment” counties. These nonattainment counties were required to reduce particulate matter air pollution to come into compliance with the new standards.
We estimate that nonattainment counties delivered sharp and persistent reductions in particulate matter air pollution, relative to counties that were already in compliance, following the introduction of the Clean Air Act. Using this variation, we document that children born after the new regulations were introduced benefited from 9 months of additional clean air, compared to children who were born just before the new regulations passed. This allows us to isolate the effects of first-generation prenatal pollution exposure.
These reductions in prenatal pollution exposure not only benefitted those directly affected but also led to substantial increases in educational attainment for the children of those who were directly affected 40 years later.
How do the effects of prenatal exposure cross from one generation to the next? In addition to measuring the intergenerational effects of air pollution, we also explore the mechanisms through which intergenerational transmission arises.
On the one hand, the improvements in health associated with lower prenatal pollution exposure may have been inherited from one generation to the next—a biological transmission pathway. On the other hand, improvements in health may have translated into increased productivity and earnings as adults, providing a household environment that offered greater resources and opportunities. Using information on whether children are biological, adopted, or stepchildren, we find little evidence that the effects are biologically inherited. Instead, the intergenerational transmission mechanism appears to be driven by increased parental resources and investments.
Our findings have important policy implications. First, in considering the efficacy of current and future environmental regulations, it is important to account for broader economic considerations such as effects on education, productivity, and earnings. This suggests that future cost-benefit analyses of environmental regulations should incorporate these benefits for a more complete accounting of how reducing air pollution will affect society.
Second, our findings point to the importance of environmental quality in shaping economic opportunity. Not only do reductions in air pollution reduce disparities today, these benefits also are propagated from one generation to the next. Academics should further explore these linkages to help inform policymakers who are interested in increasing economic mobility by including improved environmental quality alongside traditional economic mobility mechanisms such as investments in education, transportation, and labor market opportunities. Recent action by the Biden administration, including Executive Order 14008, have turned the focus of environmental policy toward issues of environmental justice. Our results underline the importance of ensuring that disadvantaged communities benefit from improvements in environmental quality.
—Jonathan Colmer is an assistant professor of economics at the University of Virginia and director of the Environmental Inequality Lab. John Voorheis is a lead economist at the Center for Economic Studies at the U.S. Census Bureau.