11.9
Cournot Competition
Firms indirectly determine price through output choices, rather than avoiding price-setting altogether. Each firm assumes its competitor’s production…
The Cournot model is a market structure in which firms produce homogeneous goods and compete based on quantity rather than price.
Here, each firm assumes its rival’s output is fixed during decision-making. Each firm has identical production cost structures and chooses its output to maximize profits, where marginal revenue equals its marginal cost.
For instance, consider two firms: Firm A and Firm B.
Firm A selects its output level to maximize profit, assuming that Firm B’s output is fixed.
Similarly, Firm B determines its optimal output by assuming that Firm A’s output is fixed.
In the initial stages, each firm aims to capture half of the remaining market share after accounting for the rival’s output.
Over time, they converge to a stable outcome, and both firms occupy one-third of the total market share.
At this point, neither firm has an incentive to change its output, reaching what is known as the Nash equilibrium.
The equilibrium outputs can be represented using reaction curves, which illustrate the optimal responses of each firm given the competitor’s output
The intersection point of the two curves represents the Cournot equilibrium and reflects the firm’s profit-maximizing strategy.
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Q1: How does the Cournot model differ from other market structures?
The Cournot model is an oligopoly where firms compete on quantity rather than price, producing homogeneous goods. Each firm assumes its rival's output is fixed when making decisions and chooses output to maximize profit where marginal revenue equals marginal cost. This contrasts with perfect competition and monopoly, where firms either have no market power or complete control over pricing.
Q2: What is the Nash equilibrium in Cournot competition?
The Nash equilibrium, or Cournot-Nash equilibrium, occurs when both firms settle on production levels where neither can increase profit by changing output unilaterally. In a two-firm example, each firm initially captures half the remaining market share, but over time they converge to each occupying one-third of total market share. At this stable point, neither firm has incentive to deviate from its output decision.
Q3: How do reaction curves help determine Cournot equilibrium?
Reaction curves illustrate each firm's optimal output response given its competitor's production level. The intersection of two firms' reaction curves represents the Cournot equilibrium, where both firms have settled on profit-maximizing production levels. This graphical representation shows how firms' decisions depend on each other and where they reach a stable, mutually optimal outcome.
Q4: Why do firms in Cournot competition assume rivals' output is fixed?
Each firm assumes its competitor's output remains constant to simplify its profit-maximization decision. This assumption allows firms to focus on their own output choice based on marginal revenue equaling marginal cost. Although unrealistic, this framework helps model how firms interact strategically and eventually reach equilibrium through repeated adjustments.
Q5: How does price get determined in Cournot competition?
Firms indirectly determine price through their output choices rather than setting prices directly. Since both firms offer identical products, total market supply influences the price. When one firm increases output, total supply rises, lowering prices and reducing revenue per unit. Conversely, reducing production increases prices, potentially benefiting competitors if demand is sufficiently inelastic.
Q6: What happens when one bakery changes its production in Cournot competition?
When one bakery increases output, total supply rises, causing prices to fall and reducing revenue per loaf for both bakeries. If a bakery reduces production, prices increase, potentially benefiting the competitor—but only if demand is sufficiently inelastic. Both bakeries determine output based on marginal revenue considerations to maximize profit while maintaining market stability.
Q7: How are firms interconnected in Cournot competition?
Firms in Cournot competition are interdependent; each company's output decisions directly impact others' profitability and market conditions. The choices made by one firm influence the other's optimal response, creating a steady, predictable situation where neither firm can gain advantage without triggering a competitive reaction. This interconnection drives both firms toward equilibrium.