Abstract:     In the context of supply chain competition, how its characteristics affect firms′ green innovation is a topic which aroused hot discussion among the academia. Based on the supply chain data of listed companies in the heavy pollution industry, this paper empirically examined the impact of supplier (customer) concentration on green innovation with the help of fixed effect model. The study found that the concentration of supplier (customer) in heavily polluting enterprises is not conducive to green innovation, resulting in a "resource crowding-out" effect rather than a “resource synergy” effect, which is still valid after considering various robustness tests. The mechanism analysis found that internal incentives can weaken (reinforce) the negative impact of supplier (customer) concentration on firms′ green innovation, while external pressure only exacerbates the negative impact of supplier concentration on firms′ green innovation. The heterogeneity analysis found that the adverse effect of supplier concentration on green innovation is mainly found in non-state-owned enterprises and enterprises with stronger financial resources, the adverse effect of customer concentration is mainly found in state-owned enterprises and enterprises with lower bargaining power or weaker financial resources, while supplier (customer) concentration has no significant impact on green innovation in firms with stronger bargaining power or stronger absorptive capacity. This paper will invariably contribute to the research on green innovation from the perspective of supply chain characteristics, and it will also provide some references for enterprises on how to reasonably choose supply chain relationships.

Key words: supply chain characteristics, supplier (customer) concentration, firm′s green innovation, resource synergy, resource crowding-out