Regulatory Heterogeneity, Sanitary and Phytosanitary Harmonization Under Regional Trade Agreements, and Agricultural Trade: An Empirical Analysis Based on China's Fruit and Vegetable Exports

Regulatory conflicts arising from heterogeneous sanitary and phytosanitary (SPS) measures remain prevalent, while SPS harmonization under regional trade agreements (RTAs) serves as a pivotal mechanism to reconcile such conflicts. The interaction between regulatory heterogeneity and SPS harmonization profoundly shapes the dynamics of agricultural trade. From the dual perspectives of regional cooperation and regulatory conflicts, this study analyzes the intricate relationship between regulatory heterogeneity, SPS harmonization under RTAs, and agricultural trade. Using China's agricultural export data (2012–2018), this study empirically examines how the interplay between regulatory heterogeneity and regional SPS harmonization influences China's fruit and vegetable exports. The Ad Valorem Equivalent (AVE) is employed to quantify the economic magnitude of this interaction effect. The results show that the interaction between regulatory heterogeneity and SPS harmonization under RTAs promotes China's fruit and vegetable exports, with an AVE of ‐3.35%. Mechanism analysis indicates that this interplay affects exports by reducing trade costs and lowering mandatory entry thresholds. Heterogeneity analysis further shows that the trade benefits stemming from the interaction are concentrated in exports to low‐standard countries (−5.57%) and vegetable exports (−4.01%).