Waste import ban and water pollution: Evidence from rivers in Guangdong Province, China

This study examines the effects of China’s 2018 ban on waste imports on water quality in Guangdong Province. Using a difference-in-differences approach, we explore variations in both time and waste imports across different river sections before and after the policy implementation. The findings indicate that regions with pollution permits experienced greater improvements in water quality after the policy implementation. The ban led to significant reductions in the concentrations of mercury (13.67%,), lead (46.32%), copper (46.21%), and zinc (28.15%). These effects were particularly evident in areas with weaker environmental regulations and limited capacity for waste processing. Further analysis reveals that the reduced industrial production and stronger regulatory enforcement are the main mechanisms driving the policy impact on the improvement of water quality.