Supply — OCR GCSE Economics

Supply refers to the quantity of a good or service that producers are willing and able to sell at a given price over a specific period of time. It is a fundamental concept in economics, as it interacts with demand to determine market prices and quantities. Understanding supply helps explain how firms make production decisions and how markets allocate resources efficiently. In the OCR GCSE Economics course, you will explore the law of supply, which states that as price increases, the quantity supplied typically increases, and vice versa, assuming all other factors remain constant.

The concept of supply is crucial for analysing real-world markets, such as the housing market, agricultural markets, or the market for smartphones. For example, if the price of wheat rises, farmers are incentivised to grow more wheat, increasing the quantity supplied. However, supply is not just about price; it is also influenced by factors like production costs, technology, taxes, and subsidies. These factors can shift the entire supply curve, leading to changes in market equilibrium. Mastering supply will enable you to evaluate how businesses respond to changing economic conditions and government policies.

Supply fits into the wider subject of economics by forming one half of the supply and demand model, which is the cornerstone of microeconomics. Alongside demand, supply helps explain price determination and resource allocation. In the OCR GCSE specification, you will also learn about price elasticity of supply (PES), which measures how responsive quantity supplied is to a change in price. This topic connects to production, costs, and revenue, as well as market structures. By understanding supply, you will be better equipped to analyse issues like market failure, government intervention, and the impact of globalisation on UK businesses.

• →Law of Supply: As price increases, quantity supplied increases (ceteris paribus), leading to an upward-sloping supply curve.
• →Movement along the supply curve: Caused solely by a change in the price of the good itself, resulting in a change in quantity supplied.
• →Shift of the supply curve: Caused by changes in non-price factors (e.g., costs of production, technology, taxes, subsidies, number of sellers), leading to a change in supply.
• →Price Elasticity of Supply (PES): Measures the responsiveness of quantity supplied to a change in price. PES = (% change in quantity supplied) / (% change in price). Supply can be elastic (PES > 1), inelastic (PES < 1), or unit elastic (PES = 1).
• →Factors affecting PES: Time period (longer time allows more flexibility), availability of raw materials, spare capacity, and ease of storage.

• Definition of supply
• Drawing and explaining supply curves using data
• Distinguishing between individual and market supply
• Drawing shifts of and movements along the supply curve
• Explaining causes and consequences of shifts and movements for consumers and producers
• Defining price elasticity of supply
• Drawing supply curves of different elasticity
• Evaluating the importance of price elasticity of supply for consumers and producers

• 💡Ensure you can accurately draw and label supply curves as per the specification requirements.
• 💡Practice distinguishing between a movement along the curve (caused by price changes) and a shift of the curve (caused by non-price factors).
• 💡Be prepared to apply quantitative skills to supply data.
• 💡Use logical chains of reasoning when analysing the consequences of supply changes for consumers and producers.
• 💡Always use the correct terminology: distinguish between 'change in supply' (shift) and 'change in quantity supplied' (movement). Examiners look for precise language, especially in 6-mark questions.
• 💡When drawing supply diagrams, label axes correctly (Price on vertical, Quantity on horizontal), and clearly show shifts with arrows and labels (e.g., 'S1 to S2'). For PES, remember that a steeper curve indicates inelastic supply, while a flatter curve indicates elastic supply.
• 💡For evaluation, consider the time period: supply is often more elastic in the long run than the short run. Use real-world examples (e.g., agricultural supply is inelastic in the short run due to growing seasons) to support your answers.

• Misconception: 'Supply and quantity supplied are the same thing.' Correction: Supply refers to the entire relationship between price and quantity supplied (the whole curve), while quantity supplied is a specific point on the curve at a given price. A change in price causes a change in quantity supplied (movement along the curve), not a change in supply (shift of the curve).
• Misconception: 'If price increases, supply always increases.' Correction: While the law of supply suggests a positive relationship, supply can be fixed in the short run (e.g., perishable goods or limited production capacity). Also, supply can decrease if non-price factors change, even if price rises.
• Misconception: 'A shift in the supply curve is the same as a movement along it.' Correction: A shift occurs when factors other than price change (e.g., lower costs increase supply, shifting the curve right). A movement along the curve is only due to a change in the good's own price.