Optimum population is the ideal number of people in a country that creates the highest standard of living. This level is reached when the available natural resources and capital stock are used most efficiently.

The concept works in two ways:

• If the population is too small, there is not enough labour to make full use of the country’s resources.
• If the population is too large, the country experiences diminishing returns, and the amount of goods or wealth produced per person begins to drop.

It is important to remember that this is a theoretical concept. In the real world, it is very hard to calculate because technology and the availability of resources are constantly changing.