What this practice covers
These questions are drawn from past IB Economics papers and filtered to elasticity of supply (pes). You answer, you find out immediately whether you were right, and you get the reasoning for the correct option and for each distractor. Wrong answers go to a mistakes locker so you can come back to exactly those.
Practice is free. You need an account only so your progress and your mistakes are still there next time.
Start practising concept drills →
What examiners see students get wrong here
These are the errors that cost marks on elasticity of supply (pes), taken from our own topic notes. Read them before you practise and you will recognise the traps in the questions.
- Giving PES a negative sign. It is normally positive, because supply slopes upward.
- Confusing PES with PED, or applying the "total revenue test" to PES, that test belongs to PED.
- Ignoring the time period. "Supply is inelastic" is incomplete without saying over what horizon.
- Judging elasticity from the steepness of a straight-line supply curve rather than from where it cuts an axis.
- Treating spare capacity and stocks as the same thing. Capacity is about the ability to produce more; stocks are about releasing what already exists.
- Calculating PES correctly and never interpreting it.
- Saying primary products have inelastic supply without explaining why (fixed land, long production periods, weather).
- Presenting buffer stocks as straightforwardly effective.
Revise it first
If any of the above is unfamiliar, work through the notes before practising: Elasticity of Supply (PES) revision notes.