(a) What is under-population? (b) Under what conditions will it be advantageous for a country to promote population growth?

(a) Under-population is a situation in which a country's population is too small relative to its available resources (land, capital and natural resources) to make the best use of them. At this point the resources are not fully or efficiently exploited, and both per capita income and total output could rise if the population increased towards the optimum.

(b) It will be advantageous for such a country to promote population growth under the following conditions:

• Abundant unexploited resources: where large areas of fertile land and untapped natural resources remain idle for lack of labour to work them.
• Shortage of labour: where there are more jobs and productive opportunities than available workers, limiting output.
• Small domestic market: where the population is too small to support mass production, so a larger population widens demand and allows economies of scale.
• Underutilised capital and infrastructure: where factories, roads and social facilities are working below capacity for want of people to use them.
• Need for defence and security: where a larger population strengthens the labour force available for national defence.
• To reach the optimum population: where extra people would raise output per head, that is, where the country is below its optimum size.

Growth is advantageous only up to the optimum; beyond that point additional people cause over-population and falling output per head.