Cournot Competition
Cournot Oligopoly Model · Also known as: Quantity Competition, Cournot Equilibrium, Cournot-Nash Equilibrium
Cournot Competition models oligopolistic markets where firms choose quantities simultaneously, not prices. Originally formulated by Augustin-Louis Cournot in 1838, the model assumes each firm's profit depends on the total market quantity produced. The resulting Cournot-Nash Equilibrium captures the strategic interaction where each firm maximizes profit given competitors' quantities, leading to prices between monopoly and perfect competition levels.
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When to use it
Apply Cournot competition analysis when modeling oligopolies where firms are quantity setters (e.g., oil producers, agricultural commodities). Use when firms produce homogeneous goods and quantities are strategic decisions (fixed in advance, or with long lead times). Suitable for industries where capacity is the binding constraint and price adjusts to clear the market.
Strengths & limitations
- Tractable analytical framework: simple algebra yields closed-form equilibrium for many demand and cost structures
- Realistic for some industries: quantity decisions in advance is common (e.g., manufacturing, agriculture, energy)
- Flexible: extends to asymmetric firms, multiple goods, dynamic competition, and incomplete information
- Predictions fall between extremes: monopoly and perfect competition, matching empirical observations
- Assumes homogeneous goods; product differentiation alters equilibrium significantly
- Limited to simultaneous quantity moves; sequential moves (Stackelberg) yield different outcomes
- Static model; does not capture dynamic learning or capacity adjustment over time
- Perfect information assumption; incomplete information (asymmetric costs) complicates analysis
Frequently asked
How does Cournot competition differ from perfect competition?
In perfect competition, firms are price-takers and produce until price equals marginal cost, yielding zero economic profit. Cournot firms recognize their quantity impact on price and restrict production to earn positive profit, resulting in higher prices and lower total quantity than perfect competition.
Can a Cournot duopoly equilibrium be unstable?
The Cournot equilibrium is stable if best-response functions slope downward and do not intersect in a way that creates oscillations. For typical linear demand and constant marginal cost, equilibrium is stable. Non-linear demand or increasing marginal costs can yield instability.
How does the number of firms affect Cournot equilibrium price and quantity?
As the number of firms increases, total market quantity increases and price falls toward marginal cost. In the limit as n approaches infinity, Cournot equilibrium converges to perfect competition, illustrating that competition increases with market concentration.
Sources
How to cite this page
ScholarGate. (2026, June 3). Cournot Oligopoly Model. ScholarGate. https://scholargate.app/en/game-theory/cournot-competition
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
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