Section 5.1

Market Structures

Understanding the four fundamental market structures and how they shape competition, pricing, and business behavior in the economy.

Perfect Competition
Monopolistic Competition
Oligopoly
Monopoly

The Four Market Structures

Market structures are classified based on the number of firms, product differentiation, and barriers to entry.

Perfect Competition

  • Many firms: Numerous small firms, none with market power
  • Identical products: Homogeneous goods with no differentiation
  • No barriers: Free entry and exit from the market
  • Price takers: Firms accept the market price

Example: Agricultural markets (wheat, corn), foreign exchange markets

Monopolistic Competition

  • Many firms: Large number of relatively small firms
  • Differentiated products: Similar but not identical goods
  • Low barriers: Easy entry and exit
  • Some price control: Limited market power through differentiation

Example: Restaurants, clothing stores, hair salons

Oligopoly

  • Few firms: Small number of large firms dominate
  • Products vary: Can be identical or differentiated
  • High barriers: Significant obstacles to entry
  • Interdependent: Firms consider rivals' reactions

Example: Automobile industry, airlines, telecom companies, banks

Monopoly

  • Single firm: One seller controls the entire market
  • Unique product: No close substitutes available
  • Very high barriers: Entry is blocked or extremely difficult
  • Price maker: Firm sets the market price

Example: Local utilities, patented drugs, Canada Post (letter mail)

Market Structure Comparison Chart

A side-by-side comparison of key characteristics across all four market structures.

Characteristic Perfect Competition Monopolistic Competition Oligopoly Monopoly
Number of Firms Very many Many Few One
Product Type Homogeneous (identical) Differentiated Identical or differentiated Unique (no substitutes)
Barriers to Entry None Low High Very high / Blocked
Price Control None (price taker) Some Considerable Substantial (price maker)
Non-price Competition None Advertising, branding Extensive advertising Public relations
Long-run Profit Zero economic profit Zero economic profit Positive economic profit possible Positive economic profit
Real-World Examples Agriculture, forex Restaurants, retail Auto, airlines, telecom Utilities, patents

Major Barriers to Entry

Barriers to entry are obstacles that prevent new firms from entering a market. These barriers allow existing firms to maintain market power and earn economic profits.

1. Economies of Scale

When large firms can produce at significantly lower average costs than small firms, new entrants struggle to compete on price.

How it works: Existing firms spread fixed costs over large production volumes, achieving lower per-unit costs. New firms with small volumes face higher costs and cannot price competitively.

Example: Automobile manufacturing requires billions in factory investments that only make sense at high production volumes.

2. Legal Barriers

Government-granted exclusive rights that legally prevent other firms from entering a market or producing certain products.

Types include: Patents (exclusive rights to inventions for 20 years), copyrights (creative works), licenses (broadcast frequencies, taxi medallions), and franchises (exclusive service areas).

Example: Pharmaceutical companies hold patents on new drugs, preventing generic competitors for years.

3. Control of Essential Resources

When a firm owns or controls a resource that is essential for production and cannot be easily replicated or substituted.

How it works: If a key input is scarce and controlled by existing firms, new competitors cannot acquire the resources needed to produce and compete.

Example: De Beers historically controlled most of the world's diamond mines, limiting competition in the diamond industry.

4. Predatory Pricing

The practice of temporarily setting prices below cost to drive competitors out of the market or deter new entrants.

How it works: Established firms with deep financial resources can sustain short-term losses. Once competitors exit, prices are raised to recoup losses and earn profits.

Note: This practice is often illegal under competition law, but difficult to prove and prosecute.

Understanding Market Power and Competition

The spectrum from perfect competition to monopoly represents varying degrees of market power and competitive intensity.

The Spectrum of Competition

Market structures exist on a spectrum from most competitive (perfect competition) to least competitive (monopoly). The position on this spectrum determines how much control firms have over prices and how efficiently resources are allocated.

Most Competitive: Perfect Competition (Price = MC)
Moderately Competitive: Monopolistic Competition
Less Competitive: Oligopoly
Least Competitive: Monopoly (P > MC)

Market Power Defined

Market power is the ability of a firm to influence the market price of its product. Firms with market power face downward-sloping demand curves and can set prices above marginal cost.

Sources of Market Power:

  • Barriers to entry that prevent new competitors
  • Product differentiation that creates customer loyalty
  • Few competitors reducing competitive pressure
  • Control of essential resources or technology

Key Learning Objectives

By the end of this section, you should be able to:

  • 1 Identify and distinguish between the four main market structures
  • 2 Explain the key characteristics of each market structure
  • 3 Analyze how barriers to entry affect market competition

Application Skills:

  • 4 Classify real-world industries into market structure categories
  • 5 Predict firm behavior based on market structure
  • 6 Evaluate the efficiency implications of different market structures
Econ Humor

Meme Break: Market Structures Edition

When you finally understand market structures

🧠💡

"So you're telling me there are FOUR different types?"

Perfect competition, monopolistic competition, oligopoly, monopoly... got it!

Barriers to entry be like:

🚧🏃‍♂️💨

"Just start your own telecom company!"

Me: *looks at billions needed for infrastructure*

"Never mind." 😅

Learning economics doesn't have to be boring!

Continue Your Learning Journey

Now that you understand the four market structures, explore how firms in perfect competition make decisions in the short run.