Evolution and consistency analysis of plastic pollution control policies in East Asian Seas countries

The East Asian Seas region (EASR), a global hotspot of plastic pollution, is increasingly central to international cooperation in plastic waste management, facing an urgent need for effective policy solutions. While countries in EASR share commitments under UN SDGs and ASEAN declarations, policy designs remain heterogeneous and policy consistency remains underexplored. This study analyzed 74 plastic pollution control policies issued from 2000 to 2025, including 54 national-level policies in 11 EASR countries, by using quantitative content analysis and descriptive statistics. The consistency of seven representative national-level policies was further assessed by applying the policy modeling consistency (PMC) method. Results show that: (1) Policies surged after 2019 (39 % of all policies), driven by United Nations' resolutions, though only 38 % of them were legally binding. (2) Policy goals heavily focused on end-of-pipe measures, with few upstream reduction targets and poor measurability was a major insufficiency; for instance, quantitative goals in Cambodia and Malaysia only accounted for 20 % and 33 % of the total. (3) Legislative tools dominated existing policies (83 %), while market-based mechanisms such as extended producer responsibility and green public procurement were underused (43 %). (4) PMC scores indicated "perfect" policy consistency in Thailand (8.27) and Indonesia (8.50). China (6.87) and Japan (7.02) received moderate PMC scores but showed weaknesses in short-term planning, limited local-level implementation mechanisms, and insufficient financial support. These findings provide actionable insights for expanding life cycle coverage and enhancing sub-national and cross-national coordination, crucial for more effective plastic waste management and regional policy alignment in the EASR.