Chapter 17: Oligopoly

When firms collude explicitly or tacitly, they can collectively behave like a monopoly, restricting output and raising prices above competitive levels to maximize joint profits. However, each individual firm has a powerful incentive to cheat on any collusive agreement by producing more output and undercutting competitors' prices, thereby capturing a larger market share. This conflict between individual incentives and group interests leads to equilibrium outcomes that fall between the monopoly and perfectly competitive extremes. The chapter introduces game theory as the essential analytical framework, particularly the Nash equilibrium concept where each firm selects its optimal strategy given the anticipated responses of rivals. The prisoners' dilemma game demonstrates why cooperation is structurally difficult to maintain even when all parties would benefit from restraint. Repeated game interactions, exemplified by tit-for-tat strategies, show how reputation and retaliation can sustain cooperative behavior over time. Real-world applications range from OPEC's recurring struggles to enforce output quotas to airline price wars and arms races between nations, all revealing the instability inherent in collusive arrangements. The chapter then addresses government policy through antitrust legislation, particularly the Sherman Act and Clayton Act, which prohibit explicit cartels and empower enforcement through both criminal prosecution and private lawsuits. Controversial business practices such as resale price maintenance, predatory pricing, and product tying receive nuanced treatment, acknowledging that while these may appear anticompetitive on the surface, they sometimes generate consumer benefits through improved distribution, quality assurance, or technological bundling. Modern case studies including the Microsoft antitrust litigation over browser bundling and ongoing scrutiny of technology platforms illustrate how oligopoly economics directly shapes contemporary regulatory debates and business strategy.