How does social network in patent provide changes in the Chinese manufacturing firm market value?

Patent thickets create external resource constraints that reduce the market value of enterprises. In the process of technological innovation, it is no longer possible to obtain competitive advantage by relying on individual resource endowment alone. Patent cooperation is considered an important institutional element in social network relations, through which enterprises can integrate external innovation resources to counteract their shortcomings and obtain competitive advantages. In this study, 419 electronic equipment manufacturing enterprises in China between 2009 and 2019 are used as the research objects, and panel data include the financial data of enterprises, the number of patent citations, and the number of patents jointly applied for by enterprises. Based on the patent fragmentation index, social network analysis is used to construct a patent cooperation network. Using UCINET and Gephi tools, the structure of corporate patent thicket networks and their evolutionary characteristics can be obtained. A panel regression model is used to empirically test the social network effect and the effect of patent thickets on the market value of firms in the context of patent cooperation. The findings show that patent thickets can discount the market value of enterprises. However, if a firm is at the center of patent cooperation, it can obtain more innovation resources. If it is at the intermediary of cooperation, it can absorb external knowledge and technology and occupy a richer structural hole, which can positively regulate the negative effect of the patent thicket. In addition, the negative effects of patent thickets are weaker for firms with more than five years of patent maintenance compared to those with less. Our study has important implications for improving the efficiency of patent cooperation and helping governments and firms to effectively cope with patent thickets.