The work aims to examine the real form of market structure that exists today. The framework of perfect competition is an abstraction. The principle of free enterprise, its application naturally leads not to perfect competition but to monopolistic competition, which becomes and is the form of market structure typical of the application of freedom of enterprise. From this perspective, since we oscillate between competition and monopoly, the important thing is to investigate the type, degree of monopoly and above all the type of social control over oligopolies. Because this interests citizens and the efficiency of the system