Application of grafted polynomial function in forecasting cotton production trend: a step towards a sustainable cotton industry in Nigeria.

Abstract

A study was conducted to forecast cotton production trend with the application of a grafted polynomial function in Nigeria from 1985 through 2013. Grafted models are used in econometrics to embark on economic analysis involving time series. In economic time series, the paucity of data and their availability has always been a matter of concern when attempting to make appropriate forecasts and predictions. Data were sourced from the United States Department of Agriculture in respect of cotton production in Nigeria while the analysis depends just on the trend. It was shown from the graphical illustration that cotton production did not relate linearly to trend within the entire sample period. A two-time segments function (quadratic-linear) was suggested after grafting. The grafted (mean) function gave more reliable ex-post forecasts rather than merely fitting a linear function to the data used.

Key words: grafted polynomial, forecasting, cotton production, trends, Nigeria