Revise Demand and supply for Cambridge 9609 (3.1.2)

Demand represents the quantity of a good or service that consumers are willing and able to purchase at various prices over a specific period. The law of demand states an inverse relationship: as price falls, quantity demanded rises, ceteris paribus. However, the entire demand curve can shift due to non-price factors. These 'conditions of demand' include changes in consumers' disposable income, shifts in tastes and fashion, and effective advertising. The prices of other goods are also critical; a price increase for a substitute good (e.g., Pepsi) will increase demand for the original good (e.g., Coca-Cola), whilst a price increase for a complementary good (e.g., printer ink) will decrease demand for the associated product (e.g., printers).

Supply is the quantity of a product that a firm is willing and able to offer for sale at various prices over a period. The law of supply indicates a direct relationship: as the price of a good rises, firms are incentivised to supply a greater quantity. The entire supply curve can also shift due to non-price factors. Key determinants include the costs of production; a rise in raw material or labour costs will decrease supply (shift left). Technological advancements often lower production costs and increase efficiency, increasing supply (shift right). Government actions like indirect taxes increase costs and decrease supply, whereas subsidies effectively lower costs and increase supply. The price of other goods the firm could produce also influences supply decisions.

Market equilibrium occurs at the price where the quantity demanded by consumers equals the quantity supplied by producers. This is the point where the demand and supply curves intersect, establishing the equilibrium price (or market-clearing price) and equilibrium quantity. At this point, the market is stable with no tendency to change. If the market price is above equilibrium, a surplus (excess supply) occurs, pressuring firms to lower prices. If the price is below equilibrium, a shortage (excess demand) arises, allowing firms to raise prices. These market forces continually push the price back towards equilibrium. Understanding this mechanism is vital for businesses when setting prices and forecasting sales.

Marketing activities are a primary tool businesses use to deliberately shift the demand curve to the right, enabling them to sell a greater quantity at any given price point, or to sell the same quantity at a higher price. Effective promotion, such as persuasive advertising and public relations, can build brand loyalty and alter consumer tastes in the firm's favour. Product development and innovation (Product) can create new demand. Strategic pricing strategies can influence perceptions of value, whilst expanding distribution channels (Place) makes the product more accessible, increasing the number of potential consumers. The goal of marketing in this context is to make demand less sensitive to price (more inelastic) and to increase overall demand irrespective of price.