Micro 4.5 - Oligopoly and Game Theory: What you need to know for the exam!

Overview of Oligopoly

Definition:

Oligopoly is a market structure characterized by a small number of sellers, typically fewer than 10, who dominate the market. These firms hold significant market power, enabling them to influence prices and output levels.

Market Features:

  • High Barriers to Entry: The oligopoly market structure exhibits high barriers to entry, which include substantial startup costs, strong customer loyalty to existing brands, and extensive government regulations. These barriers hinder new competitors from entering the market and challenging established firms.

  • Interdependence: Firms within an oligopoly are interdependent; the actions of one firm directly impact the performance and strategies of others in the market. This interdependence often leads to price competition and strategic behavior, where companies must carefully consider their rivals' actions when making pricing and production decisions.

Examples:

  • Cell Phone Service Providers: Major companies like Verizon, AT&T, and T-Mobile dominate this sector, influencing pricing and service offerings through their competitive strategies.

  • Airlines: The airline industry is another classic example of an oligopoly, featuring key players like Delta, American Airlines, and United. Their pricing strategies and service routes affect the overall market dynamics significantly.

Oligopoly Efficiency

  • Allocative Efficiency: Oligopolies generally do not achieve allocative efficiency because they tend to price their products above marginal cost. This results in typically higher prices and lower quantities compared to perfectly competitive markets, leading to deadweight loss, where potential gains from trade are lost.

  • Productive Efficiency: Oligopolies are also not productively efficient; they do not operate at the minimum average total cost. Instead, they often function on the downward-sloping part of the average total cost curve, which implies they do not utilize resources to their fullest potential.

Game Theory in Oligopoly

  • Game Theory Definition: Game theory is a method used to analyze strategic interactions between firms, helping to understand the dynamics of competitive behavior in an oligopoly.

  • Prisoners' Dilemma: A key concept in game theory, the prisoners' dilemma illustrates the challenges of cooperation among firms in strategic situations. It highlights how individual firms may avoid cooperation due to self-interest, ultimately leading to suboptimal outcomes for all parties involved.

Payoff Matrix Discussion

  • Setup: The payoff matrix considers economic interactions between two firms (e.g., Simar Sandwiches and Ryan's Rubin) making strategic price decisions.

  • Strategies: Both firms have the option to either lower or raise their prices, leading to various potential profit outcomes.

  • Payoff Matrix: The matrix displays the potential economic profits based on the combined strategies chosen by the firms.

Collusion Outcome

  • Definition: Collusion refers to the scenario where firms work together to act like a monopoly, which is typically illegal. This cooperation leads to a reduction in competition and higher profits.

  • Finding the Best Outcome: To determine the most favorable outcome for both firms, one must identify the matrix quadrant with the highest combined profit. For instance, this might be represented in the upper left corner of the matrix with a combined profit of $1,500.

Likely Outcomes with Dominant Strategies

Analyzing Ryan's Rubin

  • Strategy Decisions:

    • If Simar Sandwiches lowers their price, Ryan's Rubin can choose to lower their price for $800 in profit or raise it for $600. The preferable choice is to lower the price.

    • If Simar Sandwiches raises their price, Ryan's Rubin can choose between earning $400 by lowering their price or $200 by raising it. Again, the lower price is the preferable option.

  • Dominant Strategy: For Ryan's Rubin, the dominant strategy is to lower the price, regardless of what Simar Sandwiches decides.

Analyzing Simar Sandwiches

  • Strategy Decisions:

    • If Ryan's Rubin lowers their price, Simar can choose to raise their price for a profit of $700 or lower it for $800. Simar would opt to lower their price in this scenario.

    • If Ryan's Rubin raises their price, Simar can decide between lowering their price for $500 or raising it for $400. Again, the best choice would be to lower the price.

  • Dominant Strategy: Simar Sandwiches does not have a dominant strategy, as their optimal choice depends on the action taken by Ryan's Rubin.

Nash Equilibrium

  • Definition: The Nash Equilibrium represents a condition where firms reach a stable outcome, such that no firm can benefit from unilaterally changing its strategy while the other firm's strategies remain unchanged. This equilibrium is critical for understanding stability in oligopolistic markets and provides insights into firms' decision-making processes under interdependence.