The Impact of China’s Waste Import Ban and Basel Convention Amendments on Global Plastic Waste Trade: A Difference-in-Differences Approach

Global trade in plastic waste was reshaped by the 2018 import ban in China and Hong Kong and the 2021 Basel Convention amendments. This study compares their impacts on HS3915 cross-border flows and the geographic redistribution of exports within a common identification framework, and examines temporal dynamics and heterogeneity linked to enforcement capacity. Using bilateral export data for 2016–2023, we estimate treatment effects via PPML DID/DDD with year and country-pair fixed effects, complemented by event-study designs and pre-trend diagnostics. Exports to China/Hong Kong underwent a one-off yet persistent contraction in 2018, whereas the 2021 amendments exhibits only a limited incremental volume effect. Diverted flows were primarily reallocated to EU gateways and selected ASEAN hubs. The originality of this study lies in the hierarchical identification of the two regulations using PPML within a common econometric context and the counterfactual quantification of the redistribution patterns. Findings indicate that environmental regulation reshapes regional divisions of labor and supply-chain resilience through rule spillovers and trade diversion. Policy implications include harmonizing standards, coordinating enforcement, and jointly developing green recycling capacity within multilateral and regional frameworks to mitigate leakage.