How regional trade policy uncertainty affects agricultural imports from third countries: evidence from the China-ASEAN free trade area

Regional trade integration and a stable policy environment are essential foundations for the high quality development of agricultural trade. The establishment of the China-ASEAN Free Trade Area deepens regional agricultural cooperation and stabilizes supply chains, while significantly altering regional trade policy uncertainty. This uncertainty directly affects intraregional agricultural trade and impacts other regions through spillover effects. However, current academic research on its third country effects and spillover transmission mechanisms remains limited. Drawing on data from the China Industrial Enterprise Database and the China Customs Database covering the years 2000–2014, this paper exploits the establishment of the China-ASEAN Free Trade Area (CAFTA) as an exogenous policy shock to construct a difference-in-differences (DID) model. The analysis investigates how regional trade policy uncertainty affects agricultural imports from third countries. The results reveal that the reduction in regional trade policy uncertainty induced by the CAFTA significantly promoted agricultural imports from non-ASEAN countries through spillover effects. This effect operates primarily through two mechanisms: the low-cost import experience effect and the linkage effect of complementary products. A decline in regional trade policy uncertainty can reduce fluctuations in agricultural import volumes, increase the diversity of both trading partners and product varieties, and ease sourcing difficulties. It can also lower tariffs, expand supply channels, and mitigate information asymmetries, thereby reducing procurement costs. Furthermore, improvements in logistics performance and storage capacity help to address transportation inefficiencies. Additional analysis shows that these third-country effects are more pronounced among medium and large enterprises, whereas micro and small firms exhibit weaker responses. This disparity is largely attributed to financing constraints, weaker innovation capacity, and limited access to international market information among smaller firms. Furthermore, this study derives policy implications from multiple perspectives, offering significant practical insights for promoting the high-quality development of the China-ASEAN Free Trade Area.