Asian Research Journal of Mathematics

Abstract

The question of Nigeria’s actual population has remained a very sensitive one within the country because there are very obvious constitutional advantages of large populations conferred on constituent parts of the Nation. This sensitivity has made it increasingly difficult to conduct a credible census exercise, and this means having to depend on projections and estimates. Projections may not take into exact account so many salient social, demographic and environmental factors that could influence or alter the nature of population abundance and structure. Along this line of reasoning, this paper examines two well-known population growth models, namely, the exponential growth model (EGM) and the logistic growth model (LGM). A simple blend of the two models through the use of an arithmetic average is proposed in an Average Projection (AP). This Average Projection is more stable than both EGM and LGM in the long run. It has the capacity to moderate the explosive tendency of the exponential model and the inexplicably converging effects of the carrying capacity in the logistic model. Projections of the population of Nigeria were made for the range of years 1991 to 2050 using the EGM, LGM and AP, and they were graphically illustrated. When compared with actual (official) projection, the average projection shows closer approximation and better stability in the long run.