An Empirical Study on the Dynamic Relationship between the Development of China’s Cross-Border E-Commerce, the Share of Foreign Trade, and Economic Growth Based on a VAR Model

With the rapid development of wireless communication infrastructure and digital information transmission technologies, cross-border e-commerce has become an important component of the global digital economy and international trade ecosystem. To investigate its interaction with macroeconomic performance, this study constructs a vector autoregression (VAR) model using annual data from 2010 to 2024 and employs impulse response analysis together with variance decomposition to examine the dynamic relationships among the total volume of cross-border e-commerce, its share in foreign trade, and China’s economic growth. The empirical results reveal significant long-term interactions among the three variables. Although expansion of cross-border e-commerce exhibits a positive self-reinforcing effect, its structural share in total foreign trade contributes more substantially to economic growth than simple scale enlargement, accounting for nearly 69% of GDP variance in the decomposition analysis. In contrast, the direct feedback effect of economic growth on cross-border e-commerce development remains relatively limited. The findings indicate that structural optimization rather than quantitative expansion constitutes the primary driver of sustainable economic development. The proposed VAR-based analytical framework provides quantitative support for policy formulation and offers valuable references for intelligent digital trade systems, wireless information transmission networks, and electromagnetic-enabled communication infrastructures that underpin next-generation cross-border commerce and smart logistics applications.