Article dans une revue: This paper provides a theory of the interactions between knowledge codification, firm-level organization structures, information diffusion and the dynamics of technological competition. At the firm level, we focus on incentives to design Knowledge Management policies based on the codification of soft into hard information. At the aggregate level, we discuss the endogenous nature of knowledge spillover and the implications for macroeconomic growth. The model predicts the existence of a bell shaped relationship between knowledge codification and technological competition.