Does Inter-firm Collaboration Network Improve Quality of Innovation? International comparative analysis from worldwide patent data (Japanese)

Using worldwide patent data and considering co-assignment as collaboration between firms, we compare the characteristics of international collaboration. Then, we examine the effect of knowledge propagation through collaboration on the quality of innovation. Introducing indices proposed in network science to capture firms' status in networks is the feature of this paper. We found collaborations of Japanese firms are less internationalized compared to other countries while Japanese firms tend to collaborate more than others, i.e., they intensively collaborate within a country. However, intensive collaboration within the country doesn't necessary improve the quality of innovation. Instead, firms bridging firms in different groups and creating various connections produce high-quality innovation. This is contrary to U.S. firms which benefit from various type of connections, including intensity of networks. This implies that it is difficult to improve innovation quality by knowledge propagation through collaboration for firms in many countries including Japan.