Price, Income and Cross Elasticity: Price, Income and Cross Elasticity
Elasticity – the concept: Elasticity – the concept The responsiveness of one variable to changes in another When price rises, what happens to demand? Demand falls BUT! How much does demand fall?
Elasticity – the concept: Elasticity – the concept If price rises by 10% - what happens to demand? We know demand will fall By more than 10%? By less than 10%? Elasticity measures the extent to which demand will change
Elasticity: Elasticity 4 basic types used: Price elasticity of demand Price elasticity of supply Income elasticity of demand Cross elasticity
Elasticity: Elasticity Price Elasticity of Demand The responsiveness of demand to changes in price Where % change in demand is greater than % change in price – elastic Where % change in demand is less than % change in price - inelastic
Elasticity: Elasticity The Formula: Ped = % Change in Quantity Demanded ___________________________ % Change in Price If answer is between 0 and -1: the relationship is inelastic If the answer is between -1 and infinity: the relationship is elastic Note: PED has – sign in front of it; because as price rises demand falls and vice-versa (inverse relationship between price and demand)
Elasticity: Elasticity Price (£) Quantity Demanded The demand curve can be a range of shapes each of which is associated with a different relationship between price and the quantity demanded.
Elasticity: Elasticity Price Quantity Demanded (000s) D The importance of elasticity is the information it provides on the effect on total revenue of changes in price. £5 100 Total revenue is price x quantity sold. In this example, TR = £5 x 100,000 = £500,000. This value is represented by the grey shaded rectangle. Total Revenue
PowerPoint Presentation: Elasticity Price Quantity Demanded (000s) D If the firm decides to decrease price to (say) £3, the degree of price elasticity of the demand curve would determine the extent of the increase in demand and the change therefore in total revenue. £5 100 £3 140 Total Revenue
Elasticity: Elasticity Price (£) Quantity Demanded 10 D 5 5 6 % Δ Price = -50% % Δ Quantity Demanded = +20% Ped = -0.4 (Inelastic) Total Revenue would fall Producer decides to lower price to attract sales Not a good move!
Elasticity: Elasticity Price (£) Quantity Demanded D 10 5 20 Producer decides to reduce price to increase sales 7 % Δ in Price = - 30% % Δ in Demand = + 300% Ped = - 10 (Elastic) Total Revenue rises Good Move!
Elasticity: Elasticity If demand is price elastic: Increasing price would reduce TR (%Δ Qd > % Δ P) Reducing price would increase TR (%Δ Qd > % Δ P) If demand is price inelastic: Increasing price would increase TR (%Δ Qd < % Δ P) Reducing price would reduce TR (%Δ Qd < % Δ P)
Elasticity: Elasticity Income Elasticity of Demand: The responsiveness of demand to changes in incomes Normal Good – demand rises as income rises and vice versa Inferior Good – demand falls as income rises and vice versa
Elasticity: Elasticity Income Elasticity of Demand: A positive sign denotes a normal good A negative sign denotes an inferior good
Elasticity: Elasticity For example: Yed = - 0.6: Good is an inferior good but inelastic – a rise in income of 3% would lead to demand falling by 1.8% Yed = + 0.4: Good is a normal good but inelastic – a rise in incomes of 3% would lead to demand rising by 1.2% Yed = + 1.6: Good is a normal good and elastic – a rise in incomes of 3% would lead to demand rising by 4.8% Yed = - 2.1: Good is an inferior good and elastic – a rise in incomes of 3% would lead to a fall in demand of 6.3%
Elasticity: Elasticity Cross Elasticity: The responsiveness of demand of one good to changes in the price of a related good – either a substitute or a complement Xed = % Δ Qd of good t __________________ % Δ Price of good y
Elasticity: Elasticity Goods which are complements : Cross Elasticity will have negative sign (inverse relationship between the two) Goods which are substitutes : Cross Elasticity will have a positive sign (positive relationship between the two)
Elasticity: Elasticity Price Elasticity of Supply: The responsiveness of supply to changes in price If Pes is inelastic - it will be difficult for suppliers to react swiftly to changes in price If Pes is elastic – supply can react quickly to changes in price Pes = % Δ Quantity Supplied ____________________ % Δ Price
Determinants of Elasticity: Determinants of Elasticity Time period – the longer the time under consideration the more elastic a good is likely to be Number and closeness of substitutes – the greater the number of substitutes, the more elastic The proportion of income taken up by the product – the smaller the proportion the more inelastic Luxury or Necessity - for example, addictive drugs
Importance of Elasticity: Importance of Elasticity Relationship between changes in price and total revenue Importance in determining what goods to tax (tax revenue) Importance in analysing time lags in production Influences the behaviour of a firm