Network Economy, Externalities and Market Structures: the Concept of Qualitative Competition

This paper aims to realize, from Rohfls' model, a micro and meso analyze of the electronic networks and of internet. In regard to the complexity of the Information and Communication System (ICS), I will add the variables that correspond to these evolutions, and I will study the new competition forms. In this regard, I will propose a typology of the different markets, and I will demonstrate why the markets where the competition is qualitative are the most competitive. In a first part, I will present Rohfls' model, I will show how the complexification of the system explains the emergence of new forms of competition, and I will highlight the limits of this model, in regard to these evolutions. In a second part, I will add some variables to Rohfls' model, and I will construct a typology of the different kinds of competition and of market structures.