World Trade Organization protesters and other globalization foes may have one less fear to fret about. Although manufacturers in the United States are churning out more and more products, their smokestacks are belching out less and less air pollution — and not just because companies are making poor countries do their dirty work. Instead, green technologies are largely clearing the air, finds Arik Levinson, a professor of economics at Georgetown University.
“A lot of [activist] groups think of the environment vs. economics as a zero-sum game,” says Levinson. “But in this case, manufacturing grew, and the environment also improved, mostly because of technological advances” that make industries cleaner, he says.
In his fine-grained analysis, Levinson first broke down the U.S. manufacturing sector into 450 separate industries. He then tracked how much air pollution (sulfur dioxide, nitrogen dioxide carbon monoxide, and volatile organic compounds) each industry generated between 1987 and 2001. Finally, he traced changes in air pollution to three different causes: growth, technologies that reduce air pollution (such as scrubbers, which clean the gasses passing through smokestacks), and importation (rather than domestic production) of environmentally unfriendly goods.
Levinson discovered that although U.S. manufacturers created 24 percent more goods, they emitted 25 percent less pollution. He estimates that the greening of manufacturing practices accounted for about 60 percent of this cleanup, whereas the shifting of polluting industries offshore accounted for only 10 percent.
Although this study did not explore what evoked the technological changes that spared America’s air, other research suggests that the Clean Air Acts of 1970 and 1977 spurred these innovations. Spikes in oil prices probably also inspired manufacturers to operate more efficiently, Levinson says.
Just because offshoring did not strongly affect America’s air does not mean that building factories abroad did not cloud the skies of other nations, concedes Levinson. “If Ford opens a factory in Mexico rather than in Detroit,” he says, “the Mexican factory could very well be more polluting” than it would have been in the United States. Yet the longitudinal data needed to explore this question are lacking, he notes. “It’s also hard to test whether pollution-intensive firms respond to regulation by relocating abroad,” he says.
Without these data, environmentalists and antiglobalization activists may still have cause to worry that corporations are doing dirtier deeds overseas. But “the United States is doing great,” says Levinson.
Arik Levinson, “Technology, International Trade, and Pollution from U.S. Manufacturing,” American Economic Review, 99, 2009.
Read more stories by Alana Conner.