DOI: 10.36347/sjpms.2021.v08i01.004

Pages: 19-28

This study examined the contribution of the various sectors to the Gross Domestic Product (GDP) of Nigeria and also developed a model for forecasting the Gross Domestic Product of Nigeria within a time frame of 33 years. Data emanating from Central Bank of Nigeria was used and analyzed using regression analysis and time series analysis. The regression results shows that the three sectors; Agricultural sector, Industrial sector and Service sector has a positive relationship and only the Industrial sector and the Service sector contribute significantly with a coefficient of 0.286, 0.631 while the contribution of the Agricultural sector is not significant with a coefficient of -0.039 implying that service sector contributes the most with 631 million naira followed by the industrial sector with 286 million naira while the agricultural sector does not contribute significantly since it decreases by 39 million naira. The contribution of the agricultural sector is not significant. A time domain model (fundamental approach) which makes use of Box Jenkins approach was applied to a developing country like Nigeria to forecast Gross domestic Product for the period 1987 to 2019 using ARIMA model. The result reveals that there is an upward trend and the First difference of the series was stationary, meaning that the series was I (1). Using expert modeler, the best model that explains the series was found to be ARIMA (1, 1, 0). The diagnosis on such model was confirmed, the error was white noise, presence of no serial correlation and a forecast for period of 10 years terms was made which indicates that GDP will continue to appreciate with these forecasted time period.