Split the class into pairs and give them to put products on the line in terms of how easy it would be to increase supply if a higher price was offered.

Have them justify their ideas and see if there are any disagreements.

Then get them to work in groups to come up with a list of factors that will make supply either harder or easier to change; they now have the factors affecting PES. Logic:

  • Wind turbines: Inelastic as per video
  • Clothes: Fairly elastic – stocks can be held, easy to increase volume given spare capacity but might be coming from Asia (therefore SR/LR issues.
  • Gold: Inelastic, but there might be stocks.
  • Mars bars: Like clothes, but more stocks in the UK
  • Bus travel: Inelastic – can’t just run new routes or change timetables. May also take time to acquire new buses.
  • Housing: Inelastic – planning (but supply of existing houses – people willing to sell might be elastic).
  • Iphones: Like clothes, but at launch operate near capacity therefore might be inelastic.
  • Itunes downloads: Infinitely elastic.
  • Olives: Pretty inelastic.
  • Mona Lisa: Totally inelastic

After this get them to work in pairs to draw what they think the supply curves will look like for:

  • Olives
  • Music downloads
  • The Mona Lisa
  • Clothes.

This should then link the idea of PES back to the diagrams.

Drag the images to the appropriate place on the value line.

Small rise in supply

Medium rise in supply

Big rise in supply