Reducing the Power of an Oligpoly

At its most simplistic definition, it is easy to understand that a monopoly is the name given to a circumstance with one seller and many buyers. Then the simple theory of supply and demand is that of a market with many sellers and many buyers. An oligopoly, on the other hand, is more than one seller, but less than many sellers. It is only logical, therefore, to ask, "What is many?" What, for example, happens if there are two sellers? Though many economists suspect that the results of two sellers are more similar to those of one seller than to those of many sellers. Where then, does thi…