Principles of Microeconomics: Oligopoly

Principles of Microeconomics - Chapter 14: Oligopoly

14.1 Market Structure in an Oligopoly

  • Definition of Oligopoly:

    • Oligopoly is a form of industry structure characterized by a small number of dominant firms.

    • Products in an oligopoly may be either homogeneous (identical) or differentiated (varied).

  • Competition in Oligopoly:

    • Oligopolists compete with each other not just on price but also in innovation, product development, marketing, and advertising strategies.

  • Five Forces Model:

    • This model, developed by Michael Porter, assists in understanding the competitiveness of an industry by analyzing five forces that impact competition and profitability:

    1. Rivalry among existing firms

    2. Threat of new entrants

    3. Bargaining power of suppliers

    4. Bargaining power of buyers

    5. Threat of substitute products

14.2 Oligopoly Models

  • Collusion Models:

    • Cartel: A coalition of firms that coordinate to make collective price and production decisions to maximize their combined profits.

    • Tacit Collusion: Occurs when firms implicitly agree to limit competition; contrasted with explicit collusion, which involves formal agreements.

  • Price Leadership Model:

    • In this model, a dominant firm sets prices that other smaller firms in the industry follow.

  • Cournot Model: illustrates that firms independently choose output levels. It demonstrates that total industry output under a duopoly is higher than under a monopoly but still less than under perfect competition.

    • Duopoly: A special case of oligopoly involving two firms.

    • Description of Cournot Model dynamics:

14.3 Game Theory

  • Game Theory:

    • An analytical framework that evaluates the strategic interactions between rival firms, individuals, or governments aiming to maximize their benefits while anticipating opponents' decisions.

  • Dominant Strategy:

    • A strategy that yields the best outcome for a player, regardless of the opponent's choice.

  • Prisoners' Dilemma:

    • A scenario where individual decision-makers act according to their own interests, leading to a worse outcome for both than if they cooperated.

  • Nash Equilibrium:

    • The point in a game where all players are using their best strategy considering the strategies of others, resulting in none having a reason to deviate from their current strategy.

  • Maximin Strategy:

    • A strategy that maximizes the minimum gain that can be derived to minimize losses.

  • Tit-for-Tat Strategy:

    • A strategy in repeated games whereby a player replicates the opponent's previous action to foster mutual cooperation.

14.5 The Role of Government

Mergers and Government Regulation:.

  • Herfindahl-Hirschman Index (HHI): Quantitative measure of market concentration that is calculated by summing the squares of the market share percentages of firms in the industry.

  • Regulatory Approaches:

    • The Department of Justice and FTC evaluate potential mergers based on whether they enhance firms' abilities for “coordinated interaction,” defined as actions that yield profits only through collective accommodating actions.

  • Debate on Government Role:

    • Government regulation is controversial; some believe government intervention is crucial to combat inefficiency and promote competition, while others argue that it could create barriers to entry and induce inefficiencies.

    • Dominant firms in one market may heavily compete in international markets, altering regulatory considerations.