There are four market models:  perfect competition, monopolistic competition, oligopoly and monopoly.  Briefly discuss the assumptions of each of these four models and give examples of each.  Explain the long run economic profit earned by each of the four.

There are four market models:  perfect competition, monopolistic competition, oligopoly and monopoly.  Briefly discuss the assumptions of each of these four models and give examples of each.  Explain the long run economic profit earned by each of the four.  Explain how the concept of economic profit might help explain the rationale for the government’s granting of monopolies to those firms that protect their product with a patent.