Enhancing supply chain resilience through green investment under emerging contaminants risk: a network game theory perspective

As emerging contaminant risks intensify, supply chains in pollution-sensitive industries have become increasingly uncertain and vulnerable. Containing pollution risk diffusion and enhancing supply chain resilience therefore constitute urgent theoretical and practical challenges. Based on inter-firm supply and demand relationships, this study constructs a network game model incorporating firm pollution sensitivity, economic exposure, and green investment. By comparing independent firm decision-making, homogeneous decision-making with network effects, and heterogeneous decision-making, this study conducts numerical simulations using data from 391 firms across six typical pollution-sensitive industries. The findings show that complementary business relationships alter the marginal returns to firms’ green investment and may induce free-riding-like strategic dependence under network externalities, thereby weakening preventive green investment incentives and increasing supply-chain network vulnerability. Firms’ green investment decisions are jointly driven by their own pollution sensitivity, potential economic losses, and partners’ risk exposure. Supply-chain topology further moderates the green investment–resilience relationship: when cooperation is limited, higher business concentration strengthens network resilience; when cooperation is intensive but structurally imbalanced, improving the green governance capacity of vulnerable firms and reducing structural asymmetry more effectively curb pollution-risk diffusion. These findings provide implications for stakeholders’ green governance and supply chain risk management decisions.