In Economics there are certain notions which, though they provide a strong emotional appeal to public opinion, possess a very ambiguous scientific content. One such notion is the concept of "economic power". The gap between its apparent precision for the layman and its ambiguity for the economist is probably a reflection of the fact that the phenomenon is very deeply built into the economic system. It is thus quite difficult to obtain a clear and objective view of the reality of economic power. According to B. Russel, "the fundamental concept in social science is power, in the same sense in which energy is the fundamental concept in physics"