Basic Economic Concepts, Scarcity, Opportunity Cost and the Production Possibility Frontier
This domain supplies the definitions and tools that Paper 1 multiple-choice and Paper 2 short-answer questions rely on: scarcity versus shortage, opportunity cost, and the production possibility frontier (PPF) as a measuring device for cost and growth.
Scarcity and choice
- Scarcity is relative: wants exceed the resources available to satisfy them at any price. It is not the same as a shortage, which is a market condition created when price is held below equilibrium and which price adjustment can clear.
- Free goods have no opportunity cost; economic goods always do.
- Every society answers three questions: what to produce, how to produce, and for whom.
Opportunity cost
- The value of the next best alternative forgone. It is measured in real goods and services, not in money, since money merely expresses the sacrifice.
- Sunk costs are already committed and are not part of opportunity cost.
The PPF
- Shows the maximum combinations of two goods producible with given resources and technology.
- It is concave to the origin because resources are imperfectly substitutable between uses, so opportunity cost rises as production switches.
- Points on the curve are productively efficient; points inside show unemployment or inefficiency; points outside are unattainable by domestic production alone.
- Movement along the curve is reallocation; an outward shift is growth from better or more resources, and such growth is usually biased towards one good.
Worked example
An economy can produce maize (tonnes) and tractors: (0, 100), (10, 90), (20, 70), (30, 40), (40, 0).
- First 10 tractors cost 10 tonnes of maize, so 1 tractor costs 1 tonne.
- The next 10 cost 20 tonnes (2 tonnes each), then 30 tonnes (3 each), then 40 tonnes (4 each). The rising figure is increasing opportunity cost.
- A point such as 25 tractors and 50 tonnes of maize lies inside the frontier: output could rise to 25 tractors with about 55 tonnes of maize at no cost in tractors, purely by removing inefficiency.
- If tractor technology improves so the maximum becomes 50 tractors while maize remains 100 tonnes, the curve pivots outwards on the tractor axis only.
Traps that cost marks
- Calling a price-control shortage scarcity, or claiming scarcity can be abolished by raising price.
- Giving opportunity cost in francs when the question asks for the alternative good forgone.
- Describing an outward shift as producing more of a good: that is a movement along the curve.
- Forgetting that trade allows consumption outside the PPF although production cannot exceed it.