External collaboration network knowledge relatedness and firm innovation capability: The moderating effect of the internal inventor collaboration network

In the context of open innovation, effectively integrating internal and external collaborative networks to leverage relevant knowledge is crucial for enhancing innovation capabilities. Current research has largely overlooked the potential non-linear effects of knowledge relatedness (similarity and complementarity) in external collaboration networks on firm innovation capability, particularly the risk of innovation suppression caused by excessive relatedness. Moreover, systematic investigation is still lacking regarding how internal inventor collaboration networks moderate this relationship. Using a sample of 189 publicly listed firms and employing social network analysis along with negative binomial regression modeling, this study addresses two key questions: (1) Does knowledge relatedness in external collaboration networks nonlinearly affect firm innovation capability? (2) How does the structure of internal collaboration networks influence this relationship? The findings reveal an inverted U-shaped relationship between both knowledge similarity (the alignment of a firm's internal knowledge) and knowledge complementarity (differences between shared resources) and firm innovation capability. Moderate levels of knowledge similarity and complementarity are most conducive to enhancing innovation capability. Furthermore, transitivity within internal inventor collaboration networks strengthens the effect of knowledge relatedness on innovation, whereas network stability weakens it. These results extend the application of absorptive capacity theory in network innovation contexts and offer a theoretical basis for firms to optimize partner selection and improve internal collaboration mechanisms.