Tariffs, exchange rates and trade barriers: the nonlinear impact of international trade policies on China's pet food exports

Based on the panel data of China's pet food exports from 2019 to 2023 and multi-source policy variables (WTO tariffs, IMF exchange rates, and EU technical regulations), this study constructs a random forest and SVR integrated model to quantify the nonlinear synergistic effects of exchange rate fluctuations, tariffs, and non-tariff barriers on exports. Through multi-stage data cleaning, policy weighted integration, and high-dimensional feature engineering, an innovative international trade policy impact mechanism on the pet industry (ITPIM-PI) is proposed, and its dynamic heterogeneity decomposition ability is verified. The core findings are as follows: (1) The price advantage of RMB depreciation is constrained by non-tariff barriers; (2) Small and medium-sized enterprises are significantly more sensitive to non-tariff barrier fluctuations than large enterprises; (3) The global demand growth threshold and export scale constitute the rigid boundary of policy effectiveness. At the theoretical level, configuration analysis reveals the configuration completeness and policy coordination threshold of the "demand-capital-technology" ternary model; at the practical level, the "exchange rate hedging-tariff flexibility-compliance construction" framework can reduce inland export costs by 12%-15% through the mutual recognition of RCEP/CPTPP standards. Future research needs to extend to long-term panel data to explore the localization adaptation index of technical standards along the “Belt and Road.