Importing air pollution? Evidence from China's plastic waste imports

Plastic waste trade has grown considerably in the last decades and has led to severe environmental problems in recipient countries. Being the largest recipient, China has permanently banned the imports of plastic waste since 2018. This paper examines the causal effect of plastic waste imports on air pollution by exploiting China's experience of importing plastic waste and the recent import ban. By combining data on plastic waste imports with PM 2.5 data at the city level for the years 2000-2011, we find that plastic waste imports increased PM 2.5 density significantly in recipient cities. To evaluate the impact of the import ban on air quality, we employ daily data on air pollution between 2015 and 2020. Our difference-in-differences results show that affected cities, relative to other cities, experienced considerable improvement in air quality following the ban. Further analysis reveals that increased incineration of non-recycled waste is the main channel. These findings provide insights into the costs of importing plastic waste and the potential environmental gains from banning such imports in other countries.