The concept of interdependence in oligopolies

In oligopolistic markets, a small number of firms dominate, and their decisions are closely linked. This interdependence means that the actions of one firm directly influence the strategies and outcomes of its competitors.

Features of interdependence

• Influence on decision-making - Firms must consider potential reactions from rivals when setting prices, output levels, or marketing strategies.
• Impact on market outcomes - The behaviour of one firm can lead to retaliatory actions from others, making it challenging to predict results without analysing competitors' perspectives.
• Examples in competitive oligopolies - Even in markets with some competition, interdependence often results in stable patterns, like consistent pricing.

This mutual reliance distinguishes oligopolies from other market structures, where firms might operate more independently.

The kinked demand curve model

The kinked demand curve model provides a framework for understanding certain behaviours in oligopolistic markets, particularly why prices tend to remain steady over time.

Purpose of the model

The model illustrates how interdependence leads to price rigidity. It assumes firms face a demand curve with a distinct bend, reflecting different elasticities above and below the current price level.

Structure of the kinked demand curve

• Upper section (elastic demand) - Above the kink, the curve is relatively flat, showing that small price increases lead to significant losses in quantity demanded.
• Lower section (inelastic demand) - Below the kink, the curve is steeper, indicating that price reductions result in only minor gains in quantity demanded.
• The kink - Occurs at the prevailing market price, where firms' expectations about rivals' reactions create a break in the curve.

This shape arises from firms' beliefs about how competitors will respond to price adjustments, leading to cautious behaviour.

Assumptions of the kinked demand curve model

The model relies on two key assumptions about how firms in an oligopoly respond to price changes by a rival.

Key assumptions:

• Response to price increases - If one firm raises its prices, competitors will not follow suit.
• Response to price decreases - If one firm lowers its prices, competitors will match the reduction.

These assumptions highlight the strategic nature of oligopolies, where firms anticipate and counter each other's moves.

Implications of the kinked demand curve for price stability

The kinked demand curve explains why firms in oligopolies often maintain stable prices, as deviations can lead to financial losses.

Effects of price changes:

• Raising prices - Leads to elastic demand, causing a substantial drop in sales as customers switch to cheaper rivals.
• Lowering prices - Results in inelastic demand, with little increase in market share since rivals match the cut.

As a result, firms lack incentives to alter prices, leading to prolonged periods of price stability.

Limitations of the kinked demand curve model

While useful, the kinked demand curve model does not apply universally to all oligopolistic markets.

Key limitations:

• Specific to certain scenarios - It describes only one possible pattern of interdependence.
• Dependence on assumptions - If the core assumptions do not hold, the model fails to predict real-world actions accurately.
• Lack of universality - Other models may better explain outcomes in different oligopolies.