Oligopoly is in between. Sound applet Structure determines whether conduct matters. Conduct doesn't matter in a perfectly competitive market, because any firm that doesn't minimize cost and keep its price low is out of business. Conduct matters considerably in monopolized markets. The monopolist may or may not take advantage of its position.
Conduct is most complex in oligopoly markets.
Conduct determines whether an oligopoly acts like a monopoly, like competition, or like something else that conforms to neither of those models. Sound applet Industries may be natural monopolies , if it is most efficient to have one seller serve an entire market. Local utility service may be an example, because it would be costly to have two sets of water pipes, electrical lines, or telephone lines to each house. Sound applet Restrict output and raise price Transfer income to themselves, a distributional issue. Efficiency is lost, because society forgoes the opportunity to turn relatively low value resources into relatively high value products.