Beyond bulk freight: How the cross-border rail infrastructure reshapes regional value chains

Amid a global shift toward the regionalization of production, large-scale infrastructure projects are expected to catalyze economic integration. However, rigorous evidence on how they reshape complex value chain networks remains scarce. This study proposes a novel methodological framework, the Bootstrap Temporal Exponential Random Graph Model with Difference-in-Differences (BTERGM-DID), to analyze the impact of a major infrastructure project, the China-Laos (C-L) Railway, on the evolution of the China-ASEAN regional value chain (RVC) network. The results indicate that cross-border high-speed rail links between inland regions can reshape the structure of RVC networks, increase links between nodes, and expand central and sub-central regions. Our findings reveal a crucial distinction that the cross-border railway's primary economic function is not that of a traditional resource corridor for bulk commodities. Instead, it operates as a value chain integration corridor, significantly intensifying linkages specifically within time-sensitive manufacturing and tradable service sectors. This research contributes a methodological toolkit for causal network analysis and provides critical evidence on the economic function of modern cross-border infrastructure. We find its value lies not merely in reducing freight costs for commodities, but in catalyzing an ecosystem of supporting services that provides the high-speed, reliable logistics necessary for deep integration into RVC.