The previous chapters have suggested that networks play a key role for coordination in the Japanese business system. In this chapter, I summarize and extend our knowledge of the extensive arsenal of social networks available to Japanese firms. I proceed in two steps. First, I describe the workings of the main mechanisms previously described in the literature: business groups, vertical keiretsu, R&D consortia, and the state-associations-firms nexus. Second, I introduce intra-industry loops, an industry-based form of informal social networks that despite its pervasiveness in the Japanese business system has largely eluded systematic exploration. Intra-industry loops represent an immediate source of industry information available to firms, and to the extent that coordination tends to occur with reference to actors that are proximate and similar, they are likely to constitute a key source of coordination and conformity pressures. To underline that Japanese firms not only have access to numerous forms of social networks, but also draw on them at relatively high levels of intensity, I conclude with a brief comparison of the prevalence of the identified kinds of networks in Japan, Germany, and the United States.

Major networks in the Japanese business system

Perhaps the best-known networking phenomenon in the Japanese business system is the business group (kigyou shuudan), also known as “horizontal keiretsu.” Scholarly interest in these networks has been intense (Caves and Uekusa 1976; Dore 1983; Gerlach 1992; Granovetter 1994; Hoshi 1994; Imai 1982, 1992, 1994; Ito 1992; Johnson 1982; Lincoln 1999; Lincoln and Gerlach 2004; Lincoln, Gerlach, and Ahmadjian 1996; Miwa and Ramseyer 2002; Nakamura 1995; Nakatani 1984; Schoppa 1997).