Market Structure: The chapter concludes with a look ahead.  This last section makes the legitimate point that market structure is also an important part of firm decision making.  The authors then lay out the four primary market structures that will be explored in the next four chapters (perfect competition, monopoly, monopolistic competition, and oligopoly).  Table 7.2 summarizes the characteristics of each and is worthy of a few minutes of lecture time.  In discussing this figure it is worth noting that both perfect competition and monopoly are clearly defined – a given market either satisfies the definition or it does not and aside from variations in the specifics of demand and cost, a market that meets the criteria of perfect competition or monopoly works exactly the same.  This is not true for the other two market structures.  Both monopolistic competition and, to an even greater degree, oligopoly can contain a large number of variations.  The text follows the conventional approach of considering the two ‘end point’ conditions first.  This is not because they are the most common or even the most important, but they do serve as important benchmarks when we consider the more realistic (and likely more interesting) cases of monopolistic competition and oligopoly.