Multilayer Network Analysis of Cross-Sector Convergence in the Bio-Industry

This study examines cross-industry convergence in the bio-industry from a multilayer network perspective. Based on quarterly industry-level indicators for five industrial layers, namely the bio-industry, digital technology, high-end equipment, new materials, and agri-food, from 2010Q2 to 2026Q1, this study constructs a directed multilayer network using lagged cross-correlations among stationarized indicator series. Each industry is represented as a network layer, and significant lagged relationships among industry-level indicators are defined as directed interlayer edges. Static interlayer density, dynamic cross-layer spillover density, overlap index, and participation coefficient are further measured to characterize the structural features, dynamic evolution, and dimensional distribution of cross-industry convergence in the bio-industry. The results show that the bio-industry is not an isolated sector, but is deeply embedded in a multilayer industrial system. The static network results reveal the strongest bidirectional connections between the bio-industry and digital technology and between the bio-industry and new materials, with high-end equipment serving as an important supporting layer. The dynamic results show that, after 2023, bidirectional spillovers between the bio-industry and digital technology, new materials, and high-end equipment strengthened markedly. The overlap index and participation coefficient further indicate that cross-industry convergence is mainly concentrated in efficiency, profitability, and per capita output dimensions, rather than merely reflecting scale expansion. Robustness checks using FDR correction and an alternative rolling-window length show that the main conclusions remain consistent. This study develops a multilayer network framework for measuring bio-industry convergence and reveals that bio-industry development is increasingly shaped by dynamic, bidirectional, and cross-layer interactions among data, materials, equipment, and application systems.