In an increasingly interconnected world, "Communication Networks Economy" provides the rational understanding necessary to provide universal access to communication means in an efficient way. This book presents the principal elements of the economics of a network as it stands today, taking into account experiences of technicians in the field. The author gives a simplified picture of the current situation in terms of structures and architecture of a network, bearing in mind the necessary quality of service and the profitability of investments, accompanied by references to recent economic works. An overview is given on the general themes of regulation and tariff principles, and the relations between supply and demand, from the perspectives of professional and residential users and network operators. Different aspects of the present situations of networks and the incidence of the Internet on the economy are also presented. In conclusion, the reader will obtain an overview of the most significant issues likely to influence the economics of communications networks as they are today.