Abstract

Intercensal estimate is an estimate of population between official census dates with both census counts being known. This was observed for three cases using three growth models to determine the effectiveness of models in predicting correctly the census figure. Case 1 was the use of the 1963 population census result as the base year and 1991 population census result as the launch year. Case 2 was the use of the 1991 population census result as the base year and 2006 population census result as the launch year and case 3 was the use of the 1963 population census result as the base year and 2006 population census result as the launch year. The Nigeria population census figure for the year 1963, 1991 and 2006 were used for intercensal prediction while nonlinear estimation was applied on the data sourced online from 1955-2016 for model validation. A modified Hyperbolic Exponential Growth Model (HEGM) was used along with Exponential Growth Model (EGM) in predicting population figures and Mean Square Error (MSE), Akaike Information Criteria (AIC) and Bayesian Information Criteria (BIC) were used to assess the suitability of the model on population prediction. Different values of shape parameter in the hyperbolic model were assumed to be small, moderate and high with ±0.1, ±0.5 and ±0.9 for Case 1, 2, and 3. HEGM gave the best intercensal estimate for the three cases and was preferred based on the AIC, BIC and MSE results with theta stabilized at ±0.1.

Keywords:Intercensal; Growth models; Hyperbolic growth model; Nigeria population

Abbreviations: HEGM: Hyperbolic Exponential Growth Model, EGM: Exponential Growth Model, MSE: Mean Square Error, AIC: Akaike Information Criteria, BIC: Bayesian Information Criteria