Section 6.1

Demand Differences

Exploring how demand curves differ across imperfectly competitive market structures and what this means for pricing and firm behavior.

Elastic Demand
Kinked Demand
Mutual Interdependence

Demand Curves in Imperfect Competition

Unlike perfect competition, firms in imperfectly competitive markets face downward-sloping demand curves, giving them some control over price.

Monopolist

Faces the entire market demand curve since it's the only seller.

  • Demand is relatively inelastic
  • Significant price-setting power
  • MR < P (must lower price to sell more)

Monopolistic Competitor

Faces a highly elastic downward-sloping demand due to many substitutes.

  • Demand is elastic (many substitutes)
  • Limited price-setting power
  • Product differentiation creates some loyalty

Oligopolist

Faces a kinked demand curve due to rival firm reactions.

  • Elastic above current price
  • Inelastic below current price
  • Must consider rivals' responses

The Kinked Demand Curve

The kinked demand curve model explains why prices tend to be rigid (sticky) in oligopolistic markets, even when costs change.

1 If a Firm Raises Its Price

Rivals won't follow the price increase. The firm loses many customers to competitors. Demand is elastic above the current price.

2 If a Firm Lowers Its Price

Rivals will match the price cut to avoid losing customers. The firm gains few new customers. Demand is inelastic below the current price.

The Result: Price Rigidity

Neither raising nor lowering price is attractive, so prices remain stable even when costs change moderately.

Kinked Demand Curve Graph

Price
Quantity D MR
P*
Q* Elastic Inelastic
Kinked demand curve (D)
Marginal revenue with gap (MR)
Kink point (current price/quantity)

Mutual Interdependence & Price Rigidity

Key characteristics that define oligopolistic market behavior.

Mutual Interdependence

In an oligopoly, each firm's decisions depend on the expected reactions of rival firms. This creates a strategic environment where firms must anticipate competitor responses.

Key Implications:

  • Firms cannot make decisions in isolation
  • Game theory models firm behavior
  • Actions trigger reactions from rivals
  • Strategic behavior replaces simple profit maximization

Price Rigidity

Oligopolistic prices tend to be "sticky" – they don't change frequently even when costs or demand change. The kinked demand curve explains why.

Why Prices Are Rigid:

  • Price increases → lose customers to rivals
  • Price cuts → rivals match, no gain
  • Gap in MR curve allows cost changes without price changes
  • Non-price competition becomes more attractive

Real-World Example: Canadian Wireless Industry

📱

The Players

Rogers, Bell, and Telus dominate the Canadian wireless market as an oligopoly.

💰

Price Behavior

Prices tend to be similar across carriers and change infrequently, demonstrating price rigidity.

🎯

Competition Focus

Firms compete through advertising, network coverage, and bundled services rather than price cuts.

Econ Humor

Meme Break: Oligopoly Edition

The kinked demand curve explained:

📈😤📉🤝

"I'll raise my prices!"

Competitors: *don't follow* 😎

"Fine, I'll LOWER my prices!"

Competitors: *immediately match* 🏃‍♂️

"I can't win!" 😭

Canadian telecom companies:

📱🤝📱🤝📱

"Our prices are totally independent!"

*All three announce identical price increases on the same day*

"What a coincidence!" 🙄

Mutual interdependence: When firms are basically frenemies!

Continue Your Learning Journey

Now explore monopoly in depth – how monopolists set prices, maximize profits, and how governments regulate them.