Supply and Demand

Definition

Supply and demand is a fundamental economic concept that describes the relationship between the quantity of a good or service that producers are willing to sell at various prices and the quantity that consumers are willing to buy. This relationship determines the market price and the quantity exchanged between buyers and sellers.

5 Must Know Facts For Your Next Test

1. The law of supply states that as the price of a good or service increases, the quantity supplied also increases, and vice versa.
2. The law of demand states that as the price of a good or service increases, the quantity demanded decreases, and vice versa.
3. The equilibrium price and quantity are determined by the intersection of the supply and demand curves, where the quantity supplied equals the quantity demanded.
4. Factors that can shift the supply or demand curves include changes in input prices, technology, consumer preferences, and the number of buyers or sellers in the market.
5. The elasticity of demand measures the responsiveness of quantity demanded to changes in price, and it can vary depending on the availability of substitutes, the proportion of income spent on the good, and the time period considered.

Review Questions

• Explain how the laws of supply and demand interact to determine the equilibrium price and quantity in a market.
  • The laws of supply and demand state that as the price of a good or service increases, the quantity supplied increases and the quantity demanded decreases, and vice versa. The equilibrium price and quantity are determined by the intersection of the supply and demand curves, where the quantity supplied equals the quantity demanded. At the equilibrium, there is no shortage or surplus, and the market clears. Any imbalance between supply and demand will lead to a change in price that restores the equilibrium.
• Describe how changes in factors such as input prices, technology, and consumer preferences can affect the supply and demand curves and the resulting equilibrium price and quantity.
  • Changes in various factors can shift the supply and demand curves, leading to a new equilibrium price and quantity. For example, an increase in input prices for producers would shift the supply curve to the left, decreasing the quantity supplied at any given price and leading to a higher equilibrium price and lower equilibrium quantity. Conversely, an improvement in technology that increases productivity would shift the supply curve to the right, increasing the quantity supplied at any given price and leading to a lower equilibrium price and higher equilibrium quantity. Changes in consumer preferences that increase the demand for a good would shift the demand curve to the right, leading to a higher equilibrium price and quantity.
• Analyze how the concept of elasticity of demand can be used to understand consumer behavior and the impact of price changes on the quantity demanded.
  • The elasticity of demand measures the responsiveness of quantity demanded to changes in price. Goods with elastic demand, where the percentage change in quantity demanded is greater than the percentage change in price, are more sensitive to price changes. Consumers are more likely to substitute or reduce consumption of these goods when prices rise. Conversely, goods with inelastic demand, where the percentage change in quantity demanded is less than the percentage change in price, are less sensitive to price changes. Consumers are less likely to significantly reduce consumption of these goods when prices rise. Understanding the elasticity of demand for a good can help producers and policymakers predict the impact of price changes on consumer behavior and the overall market.

Related terms

Equilibrium Price: The price at which the quantity supplied equals the quantity demanded, where the market clears and there is no shortage or surplus.

Elasticity of Demand: The responsiveness of the quantity demanded to a change in price, measured by the percentage change in quantity demanded divided by the percentage change in price.

Market Equilibrium: The state of the market where the quantity supplied equals the quantity demanded, and there is no tendency for prices or quantities to change.