When high levels of pollution filled the air and waterways of American communities in the 1960’s, citizens took to the streets and marched for change on the first Earth Day in 1970—leading to major government efforts to control pollution. Today, social media has largely become the gathering place for people throughout the world. But does it effectively lead to change? A new study takes up this question.

The international team of researchers investigated if citizen pressure could improve environmental enforcement and reduce pollution, and if so, what types of citizen pressure—private or public. Exploring this in the context of China, citizen volunteers sent messages appealing for action after an industrial plant violation occurred. Some of the messages were sent privately through a government hotline or online messaging platform, others were sent through the popular Twitter-like Chinese social media site Weibo.

“We found that social media is the new ‘public street,’ galvanizing momentum for change in much the same way as a protest or march, and the more popular the social posts are, the more effective they are in generating action from the government,” says study co-author Michael Greenstone, the Milton Friedman Distinguished Service Professor in Economics and director of the Energy Policy Institute at the University of Chicago (EPIC). “More specifically, it demonstrates that providing the public with information about individual polluter’s emissions can lead to pollution reduction. This has long been hypothesized by proponents of the United States’ Toxics Release Inventory program and other similar programs elsewhere in the world.”

Greenstone and his colleagues found that the public appeals for action delivered through social media reduced violations by more than 60 percent, and decreased air and water pollution by 12.2 percent and 3.7 percent, respectively. Private appeals also led to improvements but by a lesser amount. When the visibility of the social media appeals increased through “likes” and “shares,” creating at least the appearance of growing public support, government regulators were 40 percent more likely to reply and 65 percent more likely to inspect the polluting plants.

“Our study found that social media can be a very effective, and easy, tool to involve citizens in the government process and hold regulators accountable,” says Shaoda Wang, an assistant professor at the Harris School of Public Policy and deputy faculty director for EPIC-China. “The fact that the more popular social posts spurred more action from government officials is not surprising, but does confirm that there is a lot of opportunity for citizens to participate in governance and help improve government accountability.”

The researchers also investigated the indirect impacts of citizen participation in environmental governance. Specifically, they randomized the proportion of firms that are subject to citizen appeals in each prefecture and tracked how non-appealed firms’ environmental performance was affected when a larger share of its prefecture peers received appeals. They found that increasing the amount of citizen appeals in a prefecture does not lead to higher violation rates or emissions from non-appealed firms. The implication is that citizen participation does not crowd- out other local regulatory efforts.

“Previously, this type of bottom-up citizen participation has been shown to be effective in other parts of the world, and especially in contexts where leaders are voted into power as they would feel more accountable to those electing them,” says Guojun He, associate professor in economics and management & strategy at the University of Hong Kong​ and research director at EPIC-China. “Our study provides the first experimental evidence that this type of citizen engagement can be very effective in a context like China, showing the government does feel a great sense of accountability to its people.”

Along with Greenstone, Wang and He, the study was co-authored by Mark Buntaine from the University of California, Santa Barbara, Mengdi Liu from the University of International Business and Economics, and Bing Zhang from Nanjing University.