Oligopolies

Game Theory and Dominant Strategies

  • In any scenario where both partners are involved in a decision-making process, there is often a lack of incentive for either party to deviate from their chosen strategy.
  • Attempting to divert from the set strategy can lead to negative outcomes for oneself.
  • Each participant possesses a dominant strategy which indicates that they will choose a particular outcome regardless of the action taken by the other party.
    • Example: Thomas has a specific strategy he adheres to strictly.

Overview of Game Theory

  • The discussion revolves around game theory, specifically the Prisoner's Dilemma.
    • In a Prisoner's Dilemma, the primary question is to identify whether a dominant strategy exists and what that strategy entails.
  • Central to the analysis within game theory is the concept of Nash Equilibrium:
    • A situation where no player has an incentive to change their strategy because they are already at an optimal outcome given the other players' strategies.

Characteristics of Oligopolies

  • The focus of the discussion relates to oligopolies.
    • Oligopolies consist of a market structure where a few firms dominate the market space.
    • The defining feature of oligopolies is interdependence among firms:
    • The outcome or decision-making of one firm significantly depends not only on their own actions but also on the actions of other firms in the market.
  • Firms must strategize based on potential reactions from the competition, making their decision-making process more complex.

Price and Output in Different Market Structures

  • Under oligopolies, firms may operate at different quantities and pricing strategies compared to perfectly competitive industries.
    • Example: A non-competitively priced firm will establish production where Marginal Revenue (MR) = Marginal Cost (MC).
    • This results in a lower quantity produced (denoted as Q{MC}) than a perfectly competitive firm, which produces at a higher output (denoted as QC).
  • Pricing strategies differ distinctly between competitive firms and oligopolies:
    • Competitive firms function efficiently at the lowest point of the Average Total Cost (ATC) curve, leading to productive efficiency.
    • In contrast, firms within monopolistic competition do not operate at this lowest efficiency point, leading to decreased output levels and higher pricing.

Efficiency Comparisons

  • Perfect competition is characterized by:
    • Allocative efficiency: resources are distributed in a way that maximizes total welfare.
    • Productive efficiency: production occurs at the lowest average total cost.
  • Monopolistic competition, on the other hand, does not achieve this efficiency and operates generally to the left of the ATC curve:
    • Resultantly less efficient than perfectly competitive markets.

Measuring Oligopoly: Concentration Ratios

  • There are specific methodologies to differentiate between market structures, notably through concentration ratios:
    • Four-firm concentration ratio (CR4): Measures the total market share held by the four largest firms.
    • If greater than 40%, the market is classified as an oligopoly. Less than this suggests a competitive market.
    • A more comprehensive method involves assessing all firms in a market, but this is more complex and costly.

Market Share Calculation Example

  • Consider an industry composed of 10 firms:
    • Two firms possess 14% market shares each, while the remaining eight firms have 9% each.
    • Calculation of market shares provides insight into the market landscape and competitive dynamics.

Price Stability in Oligopolies

  • Historical context involves consumer behavior in retail settings, such as shopping malls, leading to changes in price strategies:
    • In the market, firms must consider potential outcomes when adjusting prices (both up and down).
    • An increase in price by one firm may not be matched by competitors, leading to a loss of customers for the raising firm.
    • Conversely, lowering prices could lead to losses as well due to the inelastic demand response.
  • As a result, firms often choose price stability, avoiding significant deviations from their original pricing.

Kinked Demand Curve Model

  • A model describing firm behavior in oligopoly markets is the kinked demand curve:
    • Reflects that firms ignore price increases from competition but match any price decreases:
    • This leads to a kink at a specific price point (the red dot symbolizing 'You are here').
    • The demand curve is illustrated as having a kink:
    • Above the point, demand is elastic (consumers reduce quantity demanded with higher prices).
    • Below, demand is inelastic (consumers increase quantity demanded with lower prices).
  • The kink leads to price stability since firms do not want to disrupt their sales by adjusting prices.

Marginal Cost and Price Setting

  • The intersection of the kink demand curve with the marginal cost (MC) creates a unique pricing strategy:
    • Changes in MC do not significantly affect the price or output for firms in this model until a large change occurs.

Collusion and Cartels

  • In contrast, when firms work together (e.g., forming a cartel), they act as a collective monopoly:
    • This creates a central opportunity to set higher prices collectively and restrict outputs to optimize profits.
  • Price leadership occurs when a dominant firm sets a price level and other firms in the market follow suit to avoid competitive losses.
    • This cooperation, while effective, is typically illegal under competition laws in many jurisdictions.