Demand — OCR GCSE Economics

Demand is a fundamental concept in economics that refers to the quantity of a good or service that consumers are willing and able to purchase at various prices over a given period. It is not just about wanting something—consumers must have the ability to pay. Understanding demand is crucial because it helps explain how prices are determined in markets and how changes in consumer behaviour affect production and resource allocation. In the OCR GCSE Economics course, demand is studied alongside supply to form the basis of market analysis, enabling students to predict price and quantity changes in response to various factors.

The law of demand states that, all else being equal, as the price of a good rises, the quantity demanded falls, and vice versa. This inverse relationship is illustrated by a downward-sloping demand curve. However, demand is influenced by more than just price; factors such as income, tastes, advertising, and the prices of related goods (substitutes and complements) can shift the entire demand curve. Students must distinguish between movements along the demand curve (caused by price changes) and shifts of the demand curve (caused by non-price factors). Mastering demand is essential for understanding consumer behaviour, market equilibrium, and the impact of government policies like taxes and subsidies.

Demand analysis is not just theoretical—it has real-world applications. For example, businesses use demand forecasts to set prices and plan production, while governments consider demand when imposing taxes on goods like petrol or cigarettes. In the OCR GCSE exam, students are expected to interpret demand schedules and curves, calculate price elasticity of demand, and evaluate how changes in demand affect revenue and consumer surplus. A solid grasp of demand also lays the groundwork for more advanced topics such as market structures and macroeconomic policy.

• →Law of demand: As price increases, quantity demanded decreases (ceteris paribus), leading to a downward-sloping demand curve.
• →Movement along the demand curve: Caused solely by a change in the price of the good itself, resulting in a change in quantity demanded.
• →Shift of the demand curve: Caused by changes in non-price factors such as income, tastes, advertising, population, or prices of substitutes and complements.
• →Substitutes and complements: A substitute is a good that can be used in place of another (e.g., tea and coffee); a complement is a good used together with another (e.g., cars and petrol). A rise in the price of a substitute increases demand for the original good, while a rise in the price of a complement decreases demand.
• →Price elasticity of demand (PED): Measures the responsiveness of quantity demanded to a change in price. PED = % change in quantity demanded / % change in price. Elastic demand (PED > 1) means revenue falls when price rises; inelastic demand (PED < 1) means revenue rises when price rises.

• Definition of demand
• Drawing and labelling demand curves using data
• Distinction between individual and market demand
• Distinction between movements along the demand curve and shifts of the demand curve
• Analysis of causes and consequences of shifts and movements for consumers and producers
• Definition and explanation of price elasticity of demand (PED)
• Drawing demand curves of different elasticities
• Evaluation of the importance of PED for consumers and producers

• 💡Ensure all diagrams are clearly labelled with Price (P) on the y-axis and Quantity (Q) on the x-axis
• 💡Use specific economic terminology when explaining shifts (e.g., 'change in non-price factors')
• 💡When evaluating PED, always link the concept back to the impact on total revenue for producers
• 💡Practice calculating PED using percentage changes to support analytical points
• 💡Always use the phrase 'ceteris paribus' (all other things being equal) when explaining the law of demand or shifts. Examiners look for this to show you understand the assumption.
• 💡When drawing demand curves, label axes correctly: price on the vertical axis (y-axis) and quantity on the horizontal axis (x-axis). Ensure arrows show direction of shifts and label old and new curves clearly.
• 💡For elasticity questions, show your working step-by-step. Calculate percentage changes using the formula: (new - old) / old × 100. Then interpret the result: if PED > 1, demand is elastic; if PED < 1, inelastic. Relate this to total revenue: for elastic demand, price rise reduces revenue; for inelastic, price rise increases revenue.

• Confusing a shift of the demand curve with a movement along the demand curve
• Failing to label axes correctly on demand diagrams
• Incorrectly identifying the factors that cause a shift versus a movement
• Misinterpreting the significance of PED values for business decision-making
• Misconception: 'Demand is the same as want.' Correction: Demand requires both willingness and ability to pay. A consumer may want a luxury car but cannot afford it, so they do not contribute to demand.
• Misconception: 'A change in price shifts the demand curve.' Correction: A change in price causes a movement along the demand curve, not a shift. Only non-price factors shift the curve.
• Misconception: 'If demand increases, price must rise.' Correction: An increase in demand shifts the demand curve right, which, with supply constant, raises equilibrium price. However, if supply also increases, price may not rise. The statement is only true ceteris paribus.