Revision 
Elasticity & it’s importance
Did anyone watch some 
adverts? 
Did you find anything offering 0%
Elasticity 
“Elasticity is a measure of 
the extent quantity responds ? 
to which a 
to a 
change in a variable.”
Calculating P.E.D. 
P.E.D. = Percentage change in Demand 
Percentage change in Price 
% Change = Difference x 100 = _____ % 
Original
What is Price elasticity? 
• 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 
• If price rises by 10%, what happens to demand? 
• We know demand will fall 
• By more than 10%? 
or 
• By less than 10%? 
• Elasticity measures the extent to which 
demand will change
PeD Mantra…. 
Consider a 
10% increase 
in price 
• If answer is between 0 and -1 
• e.g. -0.4 or -0.8 
• The relationship is inelastic 
Consumers 
DO NOT 
react much to a 
change in price 
• If the answer is between -1 and infinity 
• e.g. -1.4 or 2 or 12.3 
• The relationship is elastic 
Consumers 
DO react 
To changes in 
prices 
21/09/14 7
Elastic or inelastic???? 
Would customers react lots (ELASTIC) 
or not much (INELASTIC)….. With the 
following PeD’s???? 
Use your 
whiteboards
Elastic or inelastic? 
-3 
Elastic 
– because a 10% increase in price 
would lead to a 30% fall in demand
Elastic or inelastic? 
-0.4 
Inelastic 
– because a 10% increase in price 
would lead to a 4% fall in demand
Elastic or inelastic? 
-0.1 
Inelastic 
– because a 10% increase in price 
would lead to a 1% fall in demand
Elastic or inelastic? 
-1.1 
Elastic 
– because a 10% increase in price 
would lead to a 11% fall in demand
Elastic or inelastic? 
-14 
Elastic 
– because a 10% increase in price 
would lead to a 140% fall in demand
5 examples of 
• Elastic 
– products or 
services 
• Inelastic 
– Products or 
services
What about the effect on 
revenue?
Using PeD to calculate changes in 
TR 
• What if a company sells 
10,000 units at £5. 
• What is their current TR? 
• TR = P x Quantity 
sold 
• TR = £5 x 10,000 = 
• £50,000 
• What if the company has 
a PeD of -0.5? 
• If they reduced their price 
– would the customers 
react a bit or loads? 
• is -0.5 inelastic or elastic? 
• INELASTIC….
Using PeD to calculate changes in 
TR 
• What if a company sells 
10,000 units at £5. 
• What is their current TR? 
• TR = P x Quantity 
sold 
• TR = £5 x 10,000 = 
£50,000 
• What if the company has 
a PeD of -0.5? 
• …. and they reduce 
their price to £4.50 
• What would happen 
to their TR now? Will 
it increase or 
decrease? 
• 1st you need to know what 
the % increase in price 
has been….?
Using PeD to calculate changes in 
TR 
• What if a company sells 
10,000 units at £5. 
• And now their price is 
£4.50 
• What is the % 
change? 
• Difference/original x 
100 = % change 
• 5 - 4.50 = 0.5 / 5 x 100 = 
-10% 
• So if the company 
originally sold 10,000 
units….. 
• And PeD is 0.5 
• And price has dropped by 
10 % 
• What will happen to 
DEMAND? 
So what’s 5% 0f 10,000 units? 
500 units 
But would that be a fall or an 
increase in sales????? 
10% x 0.5 = 5%
And the last step of the 
calculation… 
• The original Q is what would happen to the 
company TR if they changed their price from £5 
to £4.50, with original sales of 10,000? 
Original TR 
£5 x 10,000 = £50,000
And the last step of the 
calculation… 
• The original Q is what would happen to the 
company TR if they changed their price from £5 
to £4.50, with original sales of 10,000? 
Original TR 
£5 x 10,000 = £50,000 
New sales 
£4.50 x (10,000 + 500) 
= £4.50 x 10,500 
= £47,250
So a price cut …. 
Doesn’t guarantee higher 
profits!
What if they increased their price? 
• Price was £5 but now 
£5.50? 
• Price increase is 0.5/5 x 
100 = +10% 
• The company still has a 
PeD of -0.5 
• So sales will FALL by 
5% 
• 10,000 x 5% 
• = 10,000 -500 
• So £5.50 x 9,500 
• TR = £52,250 
• So an inelastic 
product will earn 
MORE REVENUE 
with a price rise!
Who needs a recap? 
If not – get on with the worksheet
Worksheet Questions… 
1. A company has a price cut from £10 to £8. What will be 
the impact on their revenue if they have a PeD of 0.8 
and originally sold 30 units? 
2. A company has a price cut from £20 to £14. What will 
be the impact on their revenue if they have a PeD of 2 
and originally sold 100 units? 
3. A company has a price rise from £15 to £16. What will 
be the impact on their revenue if they have a PeD of 2 
and originally sold 100 units?

Elasticity calculations + Homework i.e. no excuses not to try

  • 1.
    Revision Elasticity &it’s importance
  • 2.
    Did anyone watchsome adverts? Did you find anything offering 0%
  • 3.
    Elasticity “Elasticity isa measure of the extent quantity responds ? to which a to a change in a variable.”
  • 4.
    Calculating P.E.D. P.E.D.= Percentage change in Demand Percentage change in Price % Change = Difference x 100 = _____ % Original
  • 5.
    What is Priceelasticity? • The responsiveness of one variable to changes in another • When price rises what happens to demand? Demand falls BUT! How much does demand fall?
  • 6.
    Elasticity – theconcept • If price rises by 10%, what happens to demand? • We know demand will fall • By more than 10%? or • By less than 10%? • Elasticity measures the extent to which demand will change
  • 7.
    PeD Mantra…. Considera 10% increase in price • If answer is between 0 and -1 • e.g. -0.4 or -0.8 • The relationship is inelastic Consumers DO NOT react much to a change in price • If the answer is between -1 and infinity • e.g. -1.4 or 2 or 12.3 • The relationship is elastic Consumers DO react To changes in prices 21/09/14 7
  • 8.
    Elastic or inelastic???? Would customers react lots (ELASTIC) or not much (INELASTIC)….. With the following PeD’s???? Use your whiteboards
  • 9.
    Elastic or inelastic? -3 Elastic – because a 10% increase in price would lead to a 30% fall in demand
  • 10.
    Elastic or inelastic? -0.4 Inelastic – because a 10% increase in price would lead to a 4% fall in demand
  • 11.
    Elastic or inelastic? -0.1 Inelastic – because a 10% increase in price would lead to a 1% fall in demand
  • 12.
    Elastic or inelastic? -1.1 Elastic – because a 10% increase in price would lead to a 11% fall in demand
  • 13.
    Elastic or inelastic? -14 Elastic – because a 10% increase in price would lead to a 140% fall in demand
  • 14.
    5 examples of • Elastic – products or services • Inelastic – Products or services
  • 15.
    What about theeffect on revenue?
  • 16.
    Using PeD tocalculate changes in TR • What if a company sells 10,000 units at £5. • What is their current TR? • TR = P x Quantity sold • TR = £5 x 10,000 = • £50,000 • What if the company has a PeD of -0.5? • If they reduced their price – would the customers react a bit or loads? • is -0.5 inelastic or elastic? • INELASTIC….
  • 17.
    Using PeD tocalculate changes in TR • What if a company sells 10,000 units at £5. • What is their current TR? • TR = P x Quantity sold • TR = £5 x 10,000 = £50,000 • What if the company has a PeD of -0.5? • …. and they reduce their price to £4.50 • What would happen to their TR now? Will it increase or decrease? • 1st you need to know what the % increase in price has been….?
  • 18.
    Using PeD tocalculate changes in TR • What if a company sells 10,000 units at £5. • And now their price is £4.50 • What is the % change? • Difference/original x 100 = % change • 5 - 4.50 = 0.5 / 5 x 100 = -10% • So if the company originally sold 10,000 units….. • And PeD is 0.5 • And price has dropped by 10 % • What will happen to DEMAND? So what’s 5% 0f 10,000 units? 500 units But would that be a fall or an increase in sales????? 10% x 0.5 = 5%
  • 19.
    And the laststep of the calculation… • The original Q is what would happen to the company TR if they changed their price from £5 to £4.50, with original sales of 10,000? Original TR £5 x 10,000 = £50,000
  • 20.
    And the laststep of the calculation… • The original Q is what would happen to the company TR if they changed their price from £5 to £4.50, with original sales of 10,000? Original TR £5 x 10,000 = £50,000 New sales £4.50 x (10,000 + 500) = £4.50 x 10,500 = £47,250
  • 21.
    So a pricecut …. Doesn’t guarantee higher profits!
  • 22.
    What if theyincreased their price? • Price was £5 but now £5.50? • Price increase is 0.5/5 x 100 = +10% • The company still has a PeD of -0.5 • So sales will FALL by 5% • 10,000 x 5% • = 10,000 -500 • So £5.50 x 9,500 • TR = £52,250 • So an inelastic product will earn MORE REVENUE with a price rise!
  • 23.
    Who needs arecap? If not – get on with the worksheet
  • 24.
    Worksheet Questions… 1.A company has a price cut from £10 to £8. What will be the impact on their revenue if they have a PeD of 0.8 and originally sold 30 units? 2. A company has a price cut from £20 to £14. What will be the impact on their revenue if they have a PeD of 2 and originally sold 100 units? 3. A company has a price rise from £15 to £16. What will be the impact on their revenue if they have a PeD of 2 and originally sold 100 units?