Definition: the PPC (or production possibility frontier) shows all combinations of two goods an economy can produce in a given period when all resources are fully and efficiently employed, technology constant.
A table (simplest exam version) — an economy choosing between rice and cloth:
| Combination | Rice (‘000 t) | Cloth (‘000 m) | Opportunity cost of cloth |
|---|---|---|---|
| A | 20 | 0 | — |
| B | 18 | 1 | 2 rice |
| C | 15 | 2 | 3 rice |
| D | 11 | 3 | 4 rice |
| E | 0 | 4 | 11 rice |
What the PPC teaches (write these five points):
1. Scarcity — the frontier exists: you cannot be beyond it.
2. Choice — every point on the curve is a possible choice.
3. Opportunity cost — moving along the curve trades one good for the other (the table's last column).
4. Increasing opportunity cost — the curve is bowed outward (concave) because resources are not equally suited to both uses (fertile land grows rice poorly as factory site); each extra unit of cloth costs more rice.
5. Efficiency and growth — a point inside the curve = unemployment or inefficiency (resources idle — an economy in recession); a point on the curve = productive efficiency; a point outside is unattainable today. The curve itself shifts outward with more/better resources or technology — the picture of economic growth (and inward, with catastrophe — war, earthquake, epidemic).
Applications (learn two): defence-vs-welfare budgeting ("guns vs butter"); Nepal's development choice — exporting labour (immediate remittance) vs building productive capacity at home (long- run growth) is a live PPC debate.