The perfectly competitive market introduced in the previous section lies at one end of a spectrum of market models. At the other end is the monopoly model. It assumes a market in which there is no competition, a market in which only a single firm operates. Two models that fall between the extremes of perfect competition and monopoly are monopolistic competition and oligopoly.
In this section we will take closer look at the characteristics of a monopoly, monopolistic competition and oligopoly.