Abstract:     Over the past 40 years of reform and opening-up, a large number of hidden champions have emerged who have long been embedded in the production and manufacturing links of GVCs. By virtue of their competitive advantages in products, technologies and services, they can gradually influence and shape the existing GVCs governance structure together with leading global firms. The leap-forward transformation of the role played by hidden champions in GVCs has prompted the academic community to re-examine the implicit assumption followed by the GVCs governance theory, that is, local suppliers only assume the governance role of the "dominated", which can also provide basic support for China to re-plan its layout in GVCs and timely adjust its development strategy in the international division of labor. Therefore, it is of great theoretical and practical significance to explore the governance role of hidden champions in GVCs compared with the original "dominated" role. Based on the perspective of knowledge power, the analytical framework of "Identity-Role" theory is constructed, an exploratory multi-case study was carried out on four hidden champions. The study finds that: (1) the knowledge power of hidden champions consists of five dimensions under GVCs: technology power, marketing power, relationship power, institutional power and acceptance power. (2) In the internal governance activities under GVCs, hidden champions mainly exercise relational power, technical power, identification power and institutional power, and assume the governance role of "knowledge collaborator". (3) In the external governance activities under GVCs, hidden champions have different governance roles in relation to customers or subordinate suppliers respectively. Specifically, in the face of customers, hidden champions mainly exercise technical and relational power, and assume the governance role of "complementary player". In the face of subordinate suppliers, hidden champions mainly exercise relationship power and market power, and assume the governance role of "tractor". The theoretical contribution of this study includes two aspects: firstly, based on the knowledge power perspective, this paper identifies the multiple governance roles of hidden champions in the governance activities of GVCs through constructing a theoretical analysis framework of "Identity-Role", enriching the literature on the governance roles of suppliers in GVCs. The implicit assumption that traditional GVCs governance theory follows, namely the local supplier only assumes the governance role of the "dominated", hardly reveals the growing role of hidden champions. In contrast, this paper reveals the multiple governance roles of hidden champions under GVCs from the perspective of knowledge power by clarifying the differentiated roles and main functions of the five dimensions of knowledge power of invisible champions with "dual identities". The findings provide useful lessons for deepening research related to the governance role of suppliers under GVCs. Secondly, by constructing a constitutive dimension model of knowledge power of hidden champions under GVCs, this paper bridges the theoretical gap in the constitutive dimension of knowledge power resulting from the excessive attention of the existing researches on the global leading enterprises. The existing literature on the dimensions of knowledge power composition under GVCs has mostly focused on global dominant firms, while ignoring the emerging research subject of hidden champions, and thus rarely involve the dimensions of their knowledge power composition. In contrast, this paper deconstructs the dimensions of knowledge power composition of hidden champions under GVCs, reveals the unique dimension of "relational power", and draws on existing research results to analyze the other dimensions and their connotation characteristics, so as to build the constitutive dimension model of knowledge power of hidden champions under GVCs. The findings expand the literature on the dimensions of knowledge power constitution under GVCs. The practical enlightenment includes three aspects: firstly, hidden champions need to embed in GVCs with a more open attitude, and build long-term close relationships with more high-quality customers and subordinate suppliers to continuously acquire critical knowledge resources. Secondly, hidden champions need to improve the internal knowledge integration system to further enhance the "proprietary nature" of internal knowledge resources. Thirdly, hidden champions need to give full play to their multiple governance roles in the industry chains, and effectively transfer and utilize their own key and unique knowledge resources to drive the linkage upgrade of local industrial clusters.

Key words: global value chain, hidden champion, governance role, knowledge power, case study