IB Econ
Change in demand vs change in quantity demanded: what's the difference?
You wrote "demand fell." Did you mean demand, or quantity demanded? In IB Economics they're different claims — and mixing them up costs marks.
- IB Econ
Is consumer surplus the same as profit?
Producer surplus isn't profit, and consumer surplus isn't savings. Mix up what the areas on the diagram mean and the welfare questions fall apart.
- IB Econ
Elastic vs inelastic demand: what does 'elastic' actually mean?
You think elastic means demand changes a lot. It's a ratio, not a size — and getting it wrong flips a high-frequency revenue rule examiners test directly.
- IB Econ
Movement along vs shift in demand curve: what's the difference?
You wrote that a price change shifted demand. It didn't. It moved you along the curve — and that distinction costs marks.
- IB Econ
Movement along vs shift in supply curve: what's the difference?
You learned that a price change doesn't shift the demand curve. The same rule governs supply — and students forget to carry it across.