Demand — OCR GCSE Economics
Test yourself on Demand with OCR GCSE practice questions.
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- explain what is meant by demand
Demand exam tips
Quick Revision Summary (Key Takeaway)
Demand represents the quantity of a good or service that consumers are willing and able to buy at various prices over a given period of time. In OCR GCSE Economics, mastering the downward-sloping demand curve and distinguishing price-driven movements from non-price shifts is fundamental to understanding market resource allocation.
Topic Overview
In OCR GCSE Economics, demand forms the bedrock of microeconomic market mechanics. It explores how consumer preferences, purchasing power, and market prices interact to determine the quantity of goods and services demanded, underpinning how resources are allocated across competitive markets.
Understanding demand equips students to interpret real-world economic scenarios, from shifts caused by demographic trends and advertising to government policy responses such as taxes and subsidies. This topic establishes the essential framework needed to understand market equilibrium, elasticity, and market failure.
Key Concepts
- →The Law of Demand: States that there is an inverse relationship between price and quantity demanded, assuming all other factors remain constant ('ceteris paribus').
- →Effective Demand: Consumer desire for a good or service supported by the financial ability to purchase it.
- →Movements along the Demand Curve: Caused exclusively by a change in the price of the good itself, leading to either an extension (downward) or contraction (upward).
- →Shifts of the Demand Curve: Caused by changes in non-price determinants (e.g. consumer incomes, advertising, tastes, population, prices of substitutes and complements), moving the entire curve left or right.
Examiner Tips
- 💡Always clearly label the axes of any demand diagram: Price (P) on the vertical axis and Quantity (Q) on the horizontal axis.
- 💡When explaining shifts, explicitly state the direction ('to the right' for an increase, 'to the left' for a decrease) and refer to curve labels (e.g. from D to D1).
- 💡Use the phrase 'ceteris paribus' (all other things being equal) when discussing price changes to show examiners you understand controlled economic variables.
Common Mistakes
- Believing that an increase in price causes the demand curve to shift left. In reality, a price change causes a contraction along the existing curve, not a shift.
- Assuming demand is merely wanting a product. In economics, demand must be effective, meaning consumer desire must be backed by the ability to pay.
- Confusing complements with substitutes when evaluating price shifts. Substitutes are alternatives in competition (e.g. butter and margarine), whereas complements are goods consumed jointly (e.g. gaming consoles and video games).
Revision Plan
- 1Session 1: Memorise the exact definitions of demand, effective demand, and the law of demand; practice drawing and labelling a basic demand curve.
- 2Session 2: Learn the non-price determinants of demand using the acronym PASIFIC (Population, Advertising, Substitutes, Income, Fashion/Tastes, Interest rates, Complements).
- 3Session 3: Practice distinguish-and-explain drills contrasting price changes (movements) with non-price factors (shifts).
- 4Session 4: Work through OCR past paper 2-mark definition, 4-mark calculation, and 6-mark analysis questions under timed conditions.
Exam Question Types
- 📋Multiple choice and 1-2 mark questions testing exact definitions (e.g. defining 'effective demand' or identifying inverse relationships).
- 📋4-mark calculation or data interpretation questions using a demand schedule to find total market demand.
- 📋6-mark 'Analyse' questions requiring logical, multi-step explanations of how an external shock (e.g. a new health trend or tax) affects market demand.
Command Word Expectations (OCR)
State / Identify
Provide a brief, factual answer without explanation. Typically worth 1 mark (e.g. 'State one determinant of demand').
Explain
State an economic point, define key terms, and link it clearly to the context through cause and effect for 2 to 4 marks.
Analyse
Construct a coherent, logical chain of economic reasoning. Show sequential cause-and-effect stages (e.g. event -> impact on consumer behaviour -> effect on demand curve -> impact on equilibrium quantity) for up to 6 marks.
How Students Lose Marks (Examiner Pitfalls)
Pitfall: Confusing a movement along the demand curve with a shift of the demand curve.
❌ Weak Answer (Loses Marks):When advertising increases, the price increases so the demand moves along the curve.
Example improved answer:An increase in advertising creates a non-price factor change that increases consumer tastes and preferences for the good. Consequently, this causes an outward shift of the entire demand curve to the right from D1 to D2, showing that consumers are willing and able to purchase more at each and every price level. A movement along the curve occurs only when the product's own price changes.
Examiner Tip: Use the trigger rule: if the price of the good itself changes, it is an extension or contraction (movement along). If any external factor changes (such as income, advertising, or substitutes), it is a shift (left or right).
Pitfall: Omitting the word 'able' when defining demand, describing only a desire rather than effective demand.
❌ Weak Answer (Loses Marks):Demand is how much people want to buy a product at a certain price.
Example improved answer:Demand is the quantity of a good or service that consumers are willing and able to purchase at a given price over a specific period of time. This is known as effective demand, meaning consumer desire is backed by the financial ability to pay.
Examiner Tip: Always write 'willing and able' together in any definition or short-answer question on demand to guarantee full marks.
Step-by-Step Worked Solutions
Question: Explain the effect of a significant price reduction in electric vehicles (EVs) on the demand for petrol-powered cars. (4 marks)
- 1.Step 1: Identify the relationship between the two goods. Electric vehicles and petrol-powered cars are substitutes because they satisfy the same consumer need for personal transport.
- 2.Step 2: Explain the direct effect on the first good. A fall in the price of electric vehicles leads to an extension in demand for electric vehicles as they become relatively cheaper.
- 3.Step 3: Explain the knock-on effect on the substitute. Because consumers switch towards the cheaper alternative, the demand for petrol-powered cars decreases at all price levels.
- 4.Step 4: Conclude with the visual curve impact. This results in an inward shift of the demand curve for petrol cars to the left (from D1 to D2).
Final Answer: Electric and petrol cars are substitutes. Lower EV prices cause an extension in EV demand, leading consumers to substitute away from petrol cars. This causes an inward shift of the petrol car demand curve to the left.
Question: Table 1 shows the weekly demand for cinema tickets at a local cinema across three consumer groups: Price: £10 | Group A: 50 | Group B: 30 | Group C: 20 Price: £8 | Group A: 75 | Group B: 55 | Group C: 40 Calculate the total market demand at £8 and explain the economic rule demonstrated by the data as price drops from £10 to £8. (4 marks)
- 1.Step 1: Add the quantities demanded by each individual group at £8 to find market demand. 75 + 55 + 40 = 170 tickets.
- 2.Step 2: Compare this with the total market demand at £10: 50 + 30 + 20 = 100 tickets.
- 3.Step 3: State the economic concept. As price decreases from £10 to £8, total market demand rises from 100 to 170 tickets.
- 4.Step 4: Relate to the law of demand. This illustrates the law of demand, which states that price and quantity demanded share an inverse relationship, causing an extension in demand when price falls (ceteris paribus).
Final Answer: Total market demand at £8 is 170 tickets. This demonstrates the law of demand, showing an inverse relationship where a reduction in price leads to an extension in quantity demanded.
Active Recall Memory Test
What is the economic term for the inverse relationship between price and quantity demanded when other factors remain constant?
Key Fact: The Law of Demand.
What single factor causes a movement along a demand curve rather than a shift?
Key Fact: A change in the price of the good itself.
What happens to the demand curve for tennis balls if the price of tennis rackets rises steeply?
Key Fact: Because tennis balls and rackets are complementary goods, higher racket prices reduce racket sales and cause the demand curve for tennis balls to shift to the left (decrease).
What is the difference between a normal good and an inferior good?
Key Fact: Demand for a normal good rises as consumer income rises, whereas demand for an inferior good falls as consumer income rises.
Frequently Asked Questions
Why does the demand curve slope downwards from left to right?
The downward slope reflects the law of demand. When price falls, a good becomes more affordable relative to consumer incomes (the income effect) and more attractive relative to alternative products (the substitution effect). Furthermore, as consumers buy more units, each extra unit yields diminishing marginal utility, meaning they are only willing to buy more at lower prices.
What is the difference between a movement along and a shift of the demand curve?
A movement along the curve is caused exclusively by a change in the price of the product itself, leading to a contraction or extension in quantity demanded. A shift of the curve occurs when non-price factors (such as advertising, consumer income, or the price of related goods) change, changing the quantity demanded at every given price.
What does ceteris paribus mean in economics?
Ceteris paribus is a Latin phrase meaning 'all other things being equal' or 'holding other factors constant'. Economists use it to isolate the relationship between two specific variables—such as price and quantity demanded—without the interference of simultaneous external changes like income shifts or advertising.
What are complementary goods and substitute goods?
Substitute goods are alternatives in competitive demand; if the price of one increases, demand for the substitute shifts to the right (e.g. butter and margarine). Complementary goods are in joint demand and used together; if the price of one rises, demand for the complement shifts to the left (e.g. printers and ink cartridges).