The power of power laws and an

Although already defined in 1926 by A. Lotka, power laws are becoming more and more important since they have been found valid in social networks such as the Internet. In this paper we prove some unique properties of power laws. We show that they characterise functions with the scale-free property (also called self-similarity property) as well as functions with the product property. They also have some desirable properties above exponential ones. 1 Permanent address: Limburgs Universitair Centrum, Universitaire Campus, B-3590 Diepenbeek, Belgium.