ABSTRACTThe objective of this paper is to explore the nature and development of nonmaterial networks within establishments across the entire manufacturing sector in Japan. We generate coproduction indexes for different commodities in the Japanese economy, which enable us to recognize three types of nonmaterial linkages: technical, market and vertical. Predictably, the level of nonmaterial linkages is greater in more knowledge intensive industries. We observe that the evolution of these networks in the decade 1975 85 among the different manufacturing sectors parallels the evolution of the knowledge levels in the Japanese labor force towards higher levels of embodied knowledge.