What the curve shows
A production possibility curve (PPC) shows the maximum combinations of two goods that an economy can produce when all resources are fully and efficiently used. It illustrates scarcity, choice and opportunity cost on one diagram.
Key idea
Points on the curve = full use of resources. A point inside = resources unemployed or inefficient. A point outside = currently unattainable.
Opportunity cost on the curve
To produce more of one good, an economy must give up some of the other, because resources are limited. This sacrifice is the opportunity cost, shown by movements along the curve. The curve usually bows outward because resources are not equally suited to producing both goods.
Example
An economy making food and machines moves from producing more food to more machines. The food given up is the opportunity cost of the extra machines.
Shifts in the curve
The whole curve shifts outward when the economy grows, for example through more resources or better technology. It shifts inward if resources are lost, for example after a natural disaster.
Remember
- On the curve = efficient; inside = waste; outside = impossible now.
- Movement along the curve shows opportunity cost.
- An outward shift shows economic growth.