The term population refers to the number of people living in a particular region. The number of people in an area is of significance to an economist because it is from this number that we get the potential labour force, which is one of the most important factors of production required in the development of any economy.

The labour force is often provided by the middle aged adults. In East Africa, these numbers are still small but the population growth rates are so high and yet the resources are limited in supply and therefore, we are concerned about population in terms of size, structure, composition and distribution.

Economically, the number of people is related to the law of diminishing returns. In East Africa, or any other developing nation, the big population may not be so alarming cut the growth rate of 3-4% per annum causes alarm for the future state of economic welfare.

Structure and composition of population is not only the size of the population that matters in demography but also the structure and composition.