Spillover Effects of High-Quality Development of the Belt and Road Initiative During China’s 15th Five-Year Plan Period

Abstract

Against the backdrop of reshaped global industrial chains and China’s 15th Five-Year Plan (2026–2030) emphasizing high-standard opening-up, this paper systematically classifies multi-dimensional spillover effects of the high-quality Belt and Road Initiative (BRI). Based on institutional spillover, industrial upgrading spillover, digital-green spillover, and regional coordination spillover frameworks, this study clarifies the institutional arrangement of the “hard connectivity, soft connectivity, and people-to-people connectivity” set by the 15th Plan. Using panel data of 65 BRI co-participating economies from 2021 to 2025, empirical analysis verifies significant positive spatial spillovers in infrastructure, the digital economy, and low-carbon cooperation. Heterogeneity test shows spillover gains are larger for Global South countries with backward industrial foundations. This research supplements theoretical literature on BRI’s long-cycle externalities and proposes targeted risk-mitigation and value-amplification paths for the 15th Plan implementation stage.