Air Pollution and Trade: The Case of China

We estimate the effects of trade on air pollution in China. To address endogeneity concerns, we use an instrumental variable strategy that treats the Great Recession as an exogenous shock that differentially affected China's coastal provinces, which export a greater volume of manufacturing as they are closer to navigable waters. In our empirical analysis, we employ annual data on emissions of sulfur dioxide as well as smoke and dust at the province level from 2003 to 2015 to measure air pollution intensity (the ratio of air pollution to GDP), and we also use fine particulate matter (PM2.5) concentrations data derived from satellite imagery as a robustness check. We find that a decrease in trade intensity (the ratio of trade to GDP) by 10 percentage points (a negative trade shock similar to what occurred during the Great Recession) increases sulfur dioxide emissions intensity by about 38 percentage points. Emissions of the other two air pollutants grow by similar proportions.