What, if anything, do all firms in all four market structures have in common? “Excess capacity is the price we pay for product differentiation.” Evaluate this statement in terms of monopolistic...

What, if anything, do all firms in all four market structures have in common? “Excess capacity is the price we pay for product differentiation.” Evaluate this statement in terms of monopolistic competition. Why might a producer use a designer label to differentiate her product from that of another producer?