The goal of this work was to present the three theories that defend the monopoly and oligopoly deregulation: Demsetz critic, theory of contestable markets and theory of capture. This was achieved using bibliographic and Internet research. We support the debate concerning this economical aspect, in Brazil and other countries, alerting about problems, costs and difficulties related to the regulation and also studying some industrial cases where the deregulation has already taken place. We concluded that much reflection is necessary when dealing with industrial regulation since there are less damaging options from the point of view of competition - and therefore more pro-consumers. The regulation, defended as a protection against abusive (monopolist) prices, among other problems may become a way of monopoly perpetuation; it could set prices and taxes in high levels, by collusion between regulated and regulators; it is expensive, difficult to execute and to monitor. The deregulation, despite its importance, is relatively not much debated, even though it could be a politic to be implemented in several situations.
deregulation; competition; monopoly
