Class: Senior Secondary School 2 (SS2 / SSS 2)
Term: Second Term
Week: 7
Age: 16 years
Duration: 45 minutes
Subject: Economics
Curriculum Theme: Market Structures
Previous Lesson: Market Structure: Perfect Competition and Monopoly.
Topic: MARKET STRUCTURE
Subject Matter: Price and quantity determination under duopoly, price and quantity determination under imperfect market

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

Define duopoly and imperfect market structures.
State the key features of duopoly and other imperfect markets.
Explain how price and quantity are determined in duopoly.
Describe the general principles of price and quantity determination in imperfect markets.

Affective Domain:

Appreciate the importance of understanding different market structures in economic analysis.
Show willingness to participate in discussions about real-life market examples.

Psychomotor Domain:

Illustrate using simple conceptual graphs the determination of price and quantity in imperfect markets.
Identify firms operating in duopoly and imperfect market structures.

Discuss the implications of different market structures on consumers and producers.
Collaborate with peers to analyze market scenarios.

Reference Materials

The following resources were used in planning this lesson:

Senior Secondary Schools Education Curriculum
State Unified Scheme of Work
A. O. Taiwo (2018). Comprehensive Economics for Senior Secondary Schools. A. Johnson Publishers.
https://www.economicshelp.org/microessays/markets/duopoly/
https://www.intelligenteconomist.com/imperfect-competition/

Instructional Materials

The teacher will teach this lesson with the aid of:

Whiteboard/Chalkboard
Markers/Chalk
Prepared conceptual graphs illustrating demand and marginal revenue curves for imperfect markets.
Textbook examples of firms in different market structures.

Rationale for the Lesson

This lesson helps pupils understand how different market structures, particularly duopoly and other imperfect markets, influence the pricing and output decisions of firms. This knowledge is important for analyzing market behavior and its effects on consumers and the economy.

Prerequisite/Previous Knowledge

Pupils should have a basic understanding of market, demand, supply, and basic concepts of perfect competition.

Lesson Content/Board Summary

MARKET STRUCTURE

Introduction to Market Structure

Market structure refers to the characteristics of a market, including the number of firms, the similarity of products, the ease of entry and exit, and the level of competition. These characteristics determine how prices and quantities are set.

Duopoly

Duopoly is a specific type of oligopoly where only two firms dominate the market for a particular product or service. These two firms are highly interdependent in their decision-making regarding price and output.

The following are features of duopoly:

Only two dominant firms in the market.
Interdependence of firms, meaning one firm’s actions affect the other.
Products can be homogeneous (identical) or differentiated.
Significant barriers to entry for new firms.
Firms may engage in price wars or collusion.

Price and Quantity Determination under Duopoly

In a duopoly, price and quantity determination is complex due to the interdependence of the two firms. There is no single model, but common outcomes include:

Collusion: Firms might agree to fix prices and quantities to maximize joint profits, acting like a monopoly. This is often illegal.
Price Competition: Firms might engage in price wars, driving prices down close to marginal cost.
Non-Price Competition: Firms compete through advertising, product differentiation, and service quality rather than price.
Reaction to Rivals: Each firm sets its price and quantity based on its expectation of the rival’s actions.

Imperfect Markets (General Overview)

Imperfect competition describes market structures where individual firms have some control over the price of their products, unlike in perfect competition. This control arises from product differentiation, barriers to entry, or a small number of firms.

The following are types of imperfect markets:

Monopoly: A single firm controls the entire market for a unique product with no close substitutes.
Duopoly: Two dominant firms control the market.
Oligopoly: A few large firms dominate the market, producing either homogeneous or differentiated products.
Monopolistic Competition: Many firms sell differentiated products that are close substitutes, with relatively easy entry and exit.

Features of Imperfect Markets

The following are general features of imperfect markets:

Firms are price makers, meaning they have some influence over the price of their product.
Products can be differentiated or homogeneous.
There are often barriers to entry, which can range from moderate to very high.
Firms face a downward-sloping demand curve.
Non-price competition (e.g., advertising, branding) is common.

Price and Quantity Determination under Imperfect Markets

In imperfect markets, firms aim to maximize profits. They typically face a downward-sloping demand curve, meaning they must lower their price to sell more units. The key principle for profit maximization is producing at the output level where Marginal Cost (MC) equals Marginal Revenue (MR).

Demand Curve: The firm’s demand curve is downward sloping, indicating that it has some market power.
Marginal Revenue Curve: The marginal revenue curve lies below the demand curve.
Profit Maximization: The firm produces the quantity where MC = MR.
Pricing: Once the profit-maximizing quantity is determined, the price is set by finding the corresponding point on the demand curve at that quantity.
Role of Barriers to Entry: Barriers allow firms to maintain market power and potentially earn supernormal profits in the long run (especially in monopoly and oligopoly).

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to recall what they know about perfect competition and different types of markets they observe in their daily lives.
Pupils’ Activity: Pupils respond by mentioning concepts of many buyers and sellers, homogeneous products, and give examples like local markets.
Learning Point: Pupils connect current topic to prior knowledge and real-world observations.

Step 2: Explanation of Duopoly

Time: 8 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines duopoly, explains its key features, and provides examples of industries that operate as duopolies (e.g., specific soft drink brands, telecommunication companies in some regions).
Pupils’ Activity: Pupils listen attentively, take notes, and ask questions for clarification regarding the definition and features.
Learning Point: Pupils understand the definition and characteristics of duopoly.

Step 3: Price and Quantity Determination under Duopoly

Time: 7 minutes
Teaching Skill: Explanation/Analysis
Teacher’s Activity: The teacher explains the complexities of price and quantity determination in a duopoly, discussing concepts like interdependence, collusion, and price competition.
Pupils’ Activity: Pupils listen and discuss how the actions of one firm can affect the other in a duopoly.
Learning Point: Pupils understand that pricing in a duopoly is influenced by rivals’ actions.

Step 4: Introduction to Imperfect Markets

Time: 5 minutes
Teaching Skill: Definition/Categorization
Teacher’s Activity: The teacher introduces the concept of imperfect markets, defines them, and lists the different types such as monopoly, oligopoly, and monopolistic competition.
Pupils’ Activity: Pupils define imperfect markets and list the different types as explained by the teacher.
Learning Point: Pupils are introduced to the broader category of imperfect markets and its various forms.

Step 5: Features of Imperfect Markets

Time: 5 minutes
Teaching Skill: Elaboration
Teacher’s Activity: The teacher elaborates on the general features of imperfect markets, such as firms being price makers, product differentiation, and barriers to entry.
Pupils’ Activity: Pupils note down the features and ask questions for better understanding.
Learning Point: Pupils identify the common characteristics of imperfect market structures.

Step 6: Price and Quantity Determination under Imperfect Markets

Time: 7 minutes
Teaching Skill: Explanation/Demonstration
Teacher’s Activity: The teacher explains the general principles of price and quantity determination in imperfect markets, focusing on the downward-sloping demand curve, the marginal revenue curve, and the profit-maximizing condition (MC=MR). The teacher uses conceptual graphs to illustrate these points.
Pupils’ Activity: Pupils observe the conceptual graphs, listen to the explanation, and understand how firms in imperfect markets determine their prices and quantities.
Learning Point: Pupils learn the general mechanism of price and quantity determination in imperfect markets.

Step 7: Evaluation/Review

Time: 5 minutes
Teaching Skill: Questioning/Assessment
Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

Define duopoly.
State three features of imperfect markets.
Explain how price is generally determined in an imperfect market.
Mention two types of imperfect markets.

Pupils’ Activity: Pupils answer orally and in writing.
Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 3 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key learning points on duopoly and price/quantity determination in imperfect markets and assigns homework.
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils consolidate their understanding and prepare for further study.

Lesson Keywords

Market Structure – Characteristics of a market that influence competition.
Duopoly – A market dominated by two firms.
Imperfect Market – A market where firms have some control over prices.
Monopoly – A market with a single seller.
Oligopoly – A market dominated by a few large firms.
Monopolistic Competition – A market with many firms selling differentiated products.
Price Determination – The process by which the market price of a good or service is established.
Quantity Determination – The process by which the output level of a good or service is established.

Differentiation

For visual learners, the teacher will use clear, labelled diagrams and graphs. Kinesthetic learners will be encouraged to participate in group discussions and present their findings. Auditory learners will benefit from the teacher’s explanations and peer discussions. The teacher will provide additional simplified notes for struggling learners and challenging questions for advanced learners.

Note for teachers using this lesson plan

Teachers should ensure that pupils understand the conceptual differences between various market structures. Emphasize that in imperfect markets, firms are price makers and that profit maximization occurs where marginal cost equals marginal revenue. Encourage pupils to identify real-life examples of duopolies and other imperfect markets in Nigeria. Use simple, illustrative graphs without overly complex derivations for this level.