Economics - Elasticity
Unit 1 revision on elasticity - AS level Economics AQA
- Created by: Clodagh
- Created on: 12-04-13 14:59
View mindmap
- Elasticity
- DEFINITION: A measure of responsiveness of the quantity demanded to a change in one of the factors influencing demand
- Price Elasticity of Demand (PED)
- Measures how responsive demand is to changes in price
- Relatively elastic would mean a large change in demand
- Relatively inelastic would mean a small change in demand
- FORMULA: %change in QD divided by %change in P
- REMEMBER: You have to Q before you P!
- The law of demand states that as price falls, quantity demanded increases. There is an inverse relationship
- PED will therefore be negative
- PED is inelastic when the value lies between 0 and -1
- PED is elastic when the value is between -1 and -?
- PED will therefore be negative
- When PED = 0, there is perfectly inelastic demand. This is represented by a vertical demand curve
- When the PED = -?, the demand curve is horizontal as it is perfectly elastic
- Unitary elastic demand occurs when the PED = -1. The significance is that the percentage fall in quantity demanded is the same as the percentage change in price
- It's influences include it's degree of necessity, habit-forming goods, substitutes and time
- Necessary products have inelastic demand as consumers tend to buy them regardless of price
- Products such as tobacco tend to have price inelastic demand, as their buyers see them as necessary
- Substitutes are products with close alternatives which have elastic demand
- In the short run, consumers may not be able to find alternatives and so demand remains the same (perfectly inelastic) but over a long period of time, they become more price elastic
- If demand is elastic, then a fall in price leads to increased total revenue
- If demand is inelastic, then a fall in price leads to decreased total revenue
- Income Elasticity of Demand (YED)
- FORMULA: %change in QD divided by %change in Y
- For normal goods there is a positive relationship between income and quantity demanded, as higher incomes give more spending power to consumers
- Income elasticity of demand is usually positive
- Richer people buy more luxuries and so luxury products tend to have higher (more elastic) income elasticities of demand
- As incomes rise, people will buy fewer economy products, such as cheap cuts of meat
- These products are known as inferior goods and have a negative income elasticity of demand
- Cross Elasticity of Demand (XED)
- FORMULA: %change in QD of good Y divided by P of good X
- Complements: Where products are consumed together, such as petrol and cars
- An increase in the price of one product will lead to lower demand for the other product
- There is an inverse (negative) relationship
- An increase in the price of one product will lead to lower demand for the other product
- Substitutes: Where consumers choose between two substitutes, such as Pepsi and Coke
- An increase in the price of one product will lead to lower demand for the same product, but higher demand for the other
- There is a positive relationship
- An increase in the price of one product will lead to lower demand for the same product, but higher demand for the other
- Complements have negative XED. A high negative value suggests the two products are close complements
- Price Elasticity of Supply (PES)
- FORMULA: %change in QS divided by %change in P
- As price rises there is an increase in the quantity supplied
- This is a positive relationship and means the PES is also usually positive
- PES is inelastic if the value lies between 0 and 1
- PES is elastic when the value is greater than 1
- There is perfectly inelastic supply when PES = 0 and this is represented by a vertical supply curve
- There is perfectly elastic supply when PES = ? and this is represented by a horizontal supply curve
- Unitary elastic supply occurs when PES = 1 and this is depicted as a straight supply curve at a 45 degree angle
- It is influenced by time, spare capacity and ease of switching products
- If a price rises, it may take time to increase production because firms need to employ new resources. In the short run, supply cannot be extended much, even if the price rises a lot, so supply is inelastic
- If a factory has under-used machinery or workers, it can react quickly to higher prices and so it's PES is elastic
- If it is easy to switch manufacturing from one product to another, then supply i elastic
Similar Economics resources:
Teacher recommended
Comments
No comments have yet been made