Abstract
This paper surveys some of the most noteworthy literature on the diffusion of process technologies from the point of view of economics. It examines the main theoretical approaches to the diffusion phenomenon: epidemic and learning effects, equilibrium models associated with firm characteristics and strategic interaction. It also discusses the role of the supply side. Empirical work modelling inter-firm diffusion is reviewed, and special attention is given to the role of geography and inter-firm networking in the process of knowledge transfer and diffusion. Some suggestions for further research are presented as a conclusion.