Monopolistic Competition: Before starting this section it is worthwhile returning one more time to the general classification of market structures so students understand where this last example fits in.  The two extreme cases of perfect competition and monopoly are defined quite rigidly, with specific assumptions and characteristics defining each type of market.  In contrast, the current chapter has considered two of the big examples of oligopoly markets that are much more flexible and able to explain a wide range of behavior in situations in which a few firms act strategically.  This last case of monopolistic competition is another model that exhibits flexibility.  The assumptions are the same as in perfect competition with the exception of homogeneous products.  Furthermore, the degree of product differentiation in monopolistic competition can vary from one situation to the next, so the model helps explain a broad range of situations in which firms compete by selling similar, but not identical, products.