Across China’s industrial areas, black soot settles into people’s lungs and bronchial tubes, producing an annual epidemic of respiratory disease. That’s the result of heating homes, schools, and offices with coal. In the past, Chinese policy-makers paid only a small amount of attention to the pollution issue, believing that to force companies to clean up their smoky pollution would hold back progress. Such a policy, it was widely thought, would not be in the country’s best long-term interests, regardless of the health gains that might be made. But what if it were possible to calculate the economic costs of air pollution? If Chinese officials knew how much their country was paying for air pollution, wouldn’t they be more motivated to do something about the problem? This was the thinking of scholars involved in a large-scale interdisciplinary collaboration known as the China Project.