Economics · Grade 12 · Price Discovery: Supply and Demand · Term 1

Demand: Determinants and Shifts

Understanding the law of demand and the factors that cause the demand curve to shift.

• Ontario Curriculum Expectations
• CEE.EE.4.1
• CEE.EE.4.2

About This Topic

Market equilibrium is the point where the quantity demanded by consumers matches the quantity supplied by producers. In the Grade 12 curriculum, this is where students learn how prices function as signals in a market economy. They explore how shifts in supply and demand curves lead to new equilibrium prices and quantities, and how these changes reflect shifts in societal preferences or resource availability.

This topic is central to understanding the 'Price Determination' strand of the Ontario standards. It allows students to analyze real-world phenomena like housing shortages or fluctuating gas prices. This topic comes alive when students can physically model the patterns of a market through a mock exchange, where they experience the pressure of finding a clearing price.

Key Questions

1. Explain the inverse relationship between price and quantity demanded.
2. Analyze how changes in consumer income affect demand for normal and inferior goods.
3. Predict the impact of changing consumer tastes on market demand.

Learning Objectives

• Explain the inverse relationship between price and quantity demanded, citing the law of demand.
• Analyze how changes in consumer income impact the demand for normal and inferior goods, predicting market shifts.
• Predict the impact of changing consumer tastes and preferences on market demand curves.
• Calculate the effect of changes in the price of related goods (substitutes and complements) on the demand for a specific product.
• Evaluate how demographic changes, such as age or population size, can cause shifts in market demand.

Before You Start

Introduction to Markets and Scarcity

Why: Students need a foundational understanding of how markets function and the concept of scarcity to grasp the principles of demand.

Basic Economic Concepts: Goods and Services

Why: Familiarity with the distinction between goods and services is necessary before analyzing consumer demand for them.

Key Vocabulary

Law of Demand	A fundamental economic principle stating that, all else being equal, as the price of a good or service increases, the quantity demanded will decrease, and vice versa.
Demand Curve	A graphical representation showing the relationship between the price of a good or service and the quantity demanded at each price.
Normal Good	A good for which demand increases as consumer income rises, and demand decreases as consumer income falls.
Inferior Good	A good for which demand decreases as consumer income rises, and demand increases as consumer income falls.
Substitute Goods	Products that can be used in place of one another; an increase in the price of one leads to an increase in the demand for the other.
Complementary Goods	Products that are often used together; an increase in the price of one leads to a decrease in the demand for the other.

Watch Out for These Misconceptions

Common Misconception

Equilibrium is a 'fair' price.

What to Teach Instead

Equilibrium is simply the price where supply equals demand; it doesn't account for whether people can afford the good. Discussion-based case studies on the Toronto housing market help students distinguish between economic equilibrium and social equity.

Common Misconception

A change in price causes the demand curve to shift.

What to Teach Instead

A change in price causes a movement *along* the curve (change in quantity demanded), not a shift of the curve itself. Using interactive graphing software or physical 'human graphs' helps students see the difference between moving a line and moving along it.

Active Learning Ideas

Simulation Game: The Pit Market

Half the class are buyers with maximum prices and half are sellers with minimum costs. They must move around the room to find deals, with the teacher recording transaction prices on the board to show the emergence of an equilibrium price.

50 min·Whole Class

Inquiry Circle: Shock the Market

Groups are given a product (e.g., electric vehicles) and a 'shock' (e.g., a new lithium discovery or a change in consumer taste). They must graph the shift and explain the resulting change in equilibrium to their peers.

30 min·Small Groups

Think-Pair-Share: The Ethics of Surge Pricing

Students consider companies like Uber or airlines that use dynamic pricing. They pair up to discuss whether this is an efficient way to reach equilibrium or an unfair practice during times of high demand.

20 min·Pairs

Real-World Connections

• Retail buyers for companies like Loblaws must analyze how changing consumer incomes and preferences, influenced by economic forecasts, will affect demand for specific food products and adjust their inventory orders accordingly.
• Urban planners in Toronto use demographic data and income trends to predict future demand for housing, public transportation, and essential services, informing decisions about infrastructure development.
• Marketing professionals at Apple analyze consumer trends and the prices of competing smartphones to forecast demand for new iPhone models and plan production levels.

Assessment Ideas

Exit Ticket

Provide students with a scenario: 'The price of gasoline has increased by 15%. Describe how this might affect the demand for large, fuel-inefficient SUVs and smaller, fuel-efficient cars. Explain your reasoning using the terms substitute goods and the law of demand.'

Quick Check

Present students with a list of goods (e.g., brand-name coffee, generic cereal, movie tickets, used textbooks). Ask them to classify each as a normal good or an inferior good and briefly justify their choice based on potential changes in consumer income.

Discussion Prompt

Pose the question: 'Imagine a popular celebrity starts endorsing a specific brand of bottled water. How would this likely impact the demand for that brand? What other factors might influence the extent of this demand shift?' Guide students to consider consumer tastes and potential substitutes.

Frequently Asked Questions

What happens when a market is not in equilibrium?

If the price is too high, a surplus occurs as sellers can't find buyers. If the price is too low, a shortage occurs. In both cases, the price mechanism usually pushes the market back toward equilibrium as buyers and sellers adjust their behavior.

How do Canadian regulations affect market equilibrium?

Regulations like supply management in the dairy industry or carbon taxes shift the supply curve. These interventions change the equilibrium price and quantity, often to achieve social or environmental goals beyond simple market efficiency.

What are the best hands-on strategies for teaching market equilibrium?

Market simulations are the gold standard. When students act as buyers and sellers, they feel the incentive to lower their price to make a sale or raise it when demand is high. This 'felt' experience makes the intersection on a graph much more meaningful.

Why do prices act as signals?

Prices convey information about scarcity and value. A rising price tells producers to make more and consumers to use less, while a falling price does the opposite. This coordination happens without a central planner.