Price Elasticity of Supply AS economics revision presentation on price elasticity of supply

Price Elasticity of SupplyAS economics revision presentation on price elasticity of supply

Price Elasticity of Supply

• Price elasticity of supply (Pes) measures the relationship between change in quantity supplied and a change in price.

– When supply is elastic, producers can increase production without a rise in cost or a time delay

– When supply is inelastic, firms find it hard to change their production levels in a given time period.

• The formula for price elasticity of supply is:

– Percentage change in quantity supplied divided by the Percentage change in price

• The co-efficient of elasticity of supply is positive, because an increase in price is likely to increase the quantity supplied to the market

Price Elasticity of Supply - Measurement

ES = % change in quantity supplied% change in price

ES > 1 price-elastic supply

ES = 1 unit-elastic supply

ES < 1 price-inelastic supply

Es = 0 perfectly inelastic supply

Es = infinity perfectly elastic supply

What Determines Supply Elasticity?

• Factor substitution possibilities

– Can labour/capital be switched easily when there is a change in demand

• When factor substitution is possible, supply will tend to be elastic

• When factors are highly specialized, substitution may be harder

• Spare production capacity available

– When there is spare capacity, businesses can expand output easily without upward pressure on costs

What Determines Supply Elasticity (2)

• Stocks (inventories) available to meet demand

– A low level of stocks makes supply inelastic in the short term

– When stocks can be released onto the market, supply is elastic

• The time frame allowed

– Momentary period (fixed supply)

– Short run (inelastic supply)

– Long run (elastic supply)

• Artificial limits on supply

– E.g. the impact of patents that limit which firms can supply a product

Applying the Concept of Price Elasticity of Supply

Applying The Concept of Elasticity of Supply (1)

• Seats in a football stadium / theatre / cinema

– Short run capacity of any stadium is more or less fixed

– Long run – expansion of stadium capacity / development of a new ground

• An increase in demand for fresh salmon

– Time lags in the production process – fixed supply available to the market in momentary period (i.e. the daily catch)

– Longer term; change in the number of vessels, length of time at sea

• World supply of oil following a large rise in world demand

– Variable amount of spare capacity among the major oil producers

– Can oil stocks be put onto the market to meet the rise in demand?

– Oil supply might be inelastic if current output is close to capacity

Applying The Concept of Elasticity of Supply (1)

• The supply of drugs required to treat Anthrax

– Short term supply is dependent on stocks of product available

– If stocks are low, supply cannot increase in the short term to meet demand

– Debate over the use of patents and how this limits production in the long run

• The supply of new housing

– Planning permission + availability of land to develop + shortages of skilled labour

– Time lags in the production process – new housing developments take months to complete

Momentary Supply – Price Elasticity = Zero

Quantity Supplied (Qs)

Price (P)



Price (P)

Momentary Supply

Q1



Price (P)

Momentary Supply

P1

Q1

D1



Price (P)

Momentary Supply

P1

Q1

D1

D2

P1



Price (P)

Momentary Supply

P1

Q1

D1

D2

P1

Increase in price from P1 to P2 does not lead to a change in supply

Short Run Supply


Price (P)

Momentary Supply

P1

Q1

D1

D2

P2

Short Run Supply

Short Run Supply


Price (P)

Momentary Supply

P1

Q1

D1

D2

P2

Short Run Supply

Q2

P3

Short Run Supply


Price (P)

Momentary Supply

P1

Q1

D1

D2

P2

Short Run Supply

Q2

Increase in price from P1 to P2 does lead to a short term expansion in supply

P3

Long Run Supply Response


Price (P)

Momentary Supply

P1

Q1

D1

D2

P2

Short Run Supply

Q2

Long Run SupplyP3

Long Run Supply Response


Price (P)

Momentary Supply

P1

Q1

D1

D2

P1

Short Run Supply

Q2

Long Run Supply

Q3

P3

Long Term Response to an Increase in Demand


Price (P)

Demand

Short Run Supply

P2

P1

Q1 Q2

Long Run Supply

D2

P3

Q3

Longer time frame – supply is more elastic – larger rise in output if price P2 is sustained



Price (P)

Demand

Short Run Supply

P2

P1

Q1 Q2

Long Run Supply

D2

P3

Q3




Price (P)

Demand

Short Run Supply

P2

P1

Q1 Q2

Long Run Supply

D2

P3

Q3


Values for price elasticity of supply

• When supply is perfectly inelastic a change in price has no effect on the quantity supplied onto the market

• When supply is perfectly elastic a firm can supply any quantity at the same market price. This occurs when the firm can produce output at a constant cost per unit and it has no capacity limits to its production

• When supply is relatively inelastic a change in demand affects price more than quantity supplied

• When supply is relatively elastic. A change in demand can be met without a change in market price

Differences in Price Elasticity of Supply

Price

Quantity

Price

Quantity

Price

Quantity

Price

Quantity

Inelastic Supply Curve

Perfectly elastic supply An elastic supply curve

Perfectly inelastic supply

Elasticity of supply and changes in market demand

Price

Relatively Elastic SupplySupply responds quickly to a

change in demand

Relatively Inelastic SupplySupply responds less than

proportionately to a change in price

Supply

Supply

Quantity Quantity Q1Q2 Q3

P1

P1

P2

P3

Q1

D3D2D1

P2P3

D3D2

D1

The non-linear supply curve

Price

Quantity

P2

P3

P1

Q2Q1 Q3

P4

P5

Supply

Q4 Q5

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Price Elasticity of Supply AS economics revision presentation on price elasticity of supply