7.6 Different Market Structures

Chapter 7.6: Different Market Structures – Full Revision Notes

7.6.1 Perfect and Imperfect Competition

Perfect Competition

• Definition: A market structure with many buyers and sellers, all selling identical products.

• Characteristics:

• Many buyers and sellers, none of which can influence market price.

• Homogeneous (standardized) product.

• Perfect information for both consumers and producers.

• Freedom of entry and exit.

• Price takers: firms accept market price.

• Examples: Agricultural produce markets (wheat, eggs).

Monopolistic Competition

• Definition: A market with many sellers offering slightly differentiated products.

• Characteristics:

• Many buyers and sellers.

• Product differentiation through branding, design, or service.

• Low barriers to entry and exit.

• Firms have some control over price.

• Non-price competition (advertising, packaging).

• Examples: Restaurants, clothing brands, shampoos.

Oligopoly

• Definition: A market dominated by a few large firms.

• Characteristics:

• Few sellers with significant market share.

• Products may be homogeneous or differentiated.

• High entry and exit barriers.

• Interdependence: firms consider rivals’ actions before changing prices.

• Price rigidity: prices tend to remain stable.

• Examples: Car industry, airlines, mobile networks.

Monopoly

• Definition: A market structure with only one firm supplying a unique product with no close substitutes.

• Characteristics:

• Single seller.

• Unique product.

• Very high barriers to entry.

• Price maker: firm sets the price.

• Imperfect information.

• Types:

• Natural Monopoly: Only one firm can efficiently supply the market (e.g., water supply).

• Government Monopoly: State controls supply (e.g., postal services).

• Technological Monopoly: Based on innovation or patent.

• Geographical Monopoly: Due to location, e.g., only store in a remote village.

7.6.2 Market Structure Analysis by Key Features

7.6.3 Barriers to Entry and Exit

Legal Barriers

• Patents, licenses, government regulations, and copyrights.

Market Barriers

• Brand loyalty, customer switching costs, product differentiation.

Cost Barriers

• High startup costs, economies of scale, sunk costs.

Physical Barriers

• Ownership of essential infrastructure, distribution networks, or exclusive locations.

7.6.4 Firm Performance in Different Market Structures

Revenue and Revenue Curves

• Total Revenue (TR) = Price × Quantity.

• Average Revenue (AR) = TR / Quantity (equal to price).

• Marginal Revenue (MR) = Change in TR from selling one more unit.

Revenue Curve Shapes

• Perfect competition: TR is linear, AR and MR are horizontal (P = AR = MR).

• Imperfect competition: AR and MR curves are downward sloping, MR < AR.

Output in Short Run and Long Run

• PC (Short Run): Firms may make normal or abnormal profits.

• PC (Long Run): Only normal profit due to entry/exit.

• MC & Oligopoly (Short Run): Firms may earn abnormal profits.

• Monopoly: Can sustain abnormal profits even in long run due to high barriers.

Profit Conditions

• Normal profit: TR = TC (includes opportunity cost).

• Abnormal profit: TR > TC.

• Loss: TR < TC.

Shutdown Price

• Short-run: Firm shuts down if P < AVC.

• Long-run: Firm exits if P < ATC.

Firm’s Supply Curve (Perfect Competition)

• In the short run, the firm’s supply curve is the portion of the MC curve above AVC.

Efficiency in Market Structures

Productive Efficiency

• Lowest cost per unit (MC = AC).

• Achieved in PC in the long run.

Allocative Efficiency

• When price = marginal cost (P = MC).

• Indicates optimal distribution of goods.

X-inefficiency

• Occurs in monopolies and oligopolies due to lack of competition.

• Higher average costs due to poor management or waste.

Dynamic Efficiency

• Efficiency over time via innovation and investment.

• Monopolies may be dynamically efficient if they reinvest profits.

Contestable Markets

Key Features

• Free entry and exit.

• Low or no sunk costs.

• Threat of new entrants keeps prices competitive.

• No long-run abnormal profits, even in monopolies or oligopolies.

Implications

• Firms behave competitively to avoid losing market share.

• Profits pushed down to normal levels (AR = ATC).

Price and Non-Price Competition

Price Competition

• Reducing prices to attract consumers.

• Can lead to price wars in oligopolies.

Non-Price Competition

• Branding, quality, service, after-sales, packaging.

• More common in monopolistic competition and oligopolies.

Collusion and Game Theory

Collusion

• Firms agree (formally or tacitly) to fix prices or output.

• Can lead to cartels (e.g., OPEC).

• Illegal in many countries.

Prisoner’s Dilemma

• Explains why collusion may not last.

• Firms have an incentive to cheat to gain higher profits.

Pay-off Matrix

• A table that shows possible profits/losses of each firm’s decisions.

• Used to illustrate the strategic interdependence in oligopoly.

7.6.5 Concentration Ratio

Definition

• The proportion of total market share held by the top 4 or 8 firms.

CR4 and CR8

• CR4: Market share of top 4 firms.

• A high ratio indicates less competition and greater market power.

Use

Common measure to identify oligopoly and assess competitiveness.