Linking agricultural land use efficiency and trade policy friendliness to embodied carbon transfers:Evidence from China-ASEAN agricultural trade.

Agricultural land use efficiency (ALUE) shapes global trade-related carbon transfer. However, whether ALUE improvements translate into reduced net embodied carbon transfer (NECT) in bilateral trade, and how bilateral trade policy friendliness (TPF) between trading partners reshapes this relationship, remain unclear. Based on the trade-environment framework, New Institutional Economics, and Trade Facilitation Theory, this study applies a Double Machine Learning approach with moderation analysis to explore the ALUE-TPF-NECT relationship. ALUE is measured using the DEA-Malmquist index, and a dynamic TPF index is constructed from 90 agricultural trade policy events through textual analysis. Using China-ASEAN agricultural trade data from 2002 to 2021, we find that: (1) The growth of NECT to China and improvements in bilateral TPF between ASEAN countries and China exhibit a clear spatial mismatch: Vietnam and Myanmar account for 94.8% of NECT growth, whereas Cambodia, Laos, and Thailand contribute 43.5% of TPF improvements; (2) Improvements in ALUE are significantly and positively associated with NECT from ASEAN to China, with this association mainly driven by export-side embodied carbon rather than import-side changes; and (3) One-period lagged TPF significantly weakens the positive ALUE-NECT relationship, indicating that friendly trade policies may reduce efficiency-driven NECT. Our findings reveal that efficiency gains alone cannot reduce agricultural trade-related embodied carbon transfer, and that bilateral TPF is a necessary condition for avoiding efficiency-driven carbon leakage and achieving green trade development. ASEAN countries should jointly improve ALUE, optimize bilateral TPF with China, and strengthen the low-carbon management of export-oriented agricultural supply chains.