ISSN 2167-0447
International Journal of Agricultural Sciences ISSN 2167-0447 Vol. 6 (11), pp. 1200-1209, November, 2016. © International Scholars Journals
Full Length Research Paper
Intervention analysis of fertilizer input subsidy on maize production in Ghana
Ernest Zamanah
Department of Statistics, Faculty of Mathematical Sciences, University for Development Studies, P. O. Box 24, Navrongo, Ghana. E-mail: [email protected].
Received 15 July, 2016; Revised 26 September, 2016; Accepted 27 September, 2016 and Published 24 November, 2016
Abstract
In a response to global oil and food crisis in 2007/2008, the Ghana government introduced a fertilizer subsidy program as a measure to ease the effects of the food crisis by increasing food production through fertilizer use. Interrupted Time Series Analysis (Intervention Analysis) was used to investigate the effect of the fertilizer subsidy program on Ghana’s maize production in this work. Secondary data representing Ghana’s annual maize production from 1960 to 2015 were used for the analysis in this study. An ARIMAX model with a set of pulse functions was then developed to examine to the effect the fertilizer subsidy program. Estimation results of the ARIMAX model revealed that the fertilizer subsidy program contributed to significant improvements in maize production for 2008, 2009, 2010 and 2012. For 2011, 2013 and 2015 however, the estimation results of the ARIMAX model revealed that the fertilizer subsidy program did not contribute to significant improvements in maize production in Ghana. On the basis of the research findings, the study was concluded by indicating the need for a proper reexamination and evaluation of the implementation process of the subsidy program in order to realize significant improvements in maize production in Ghana.
Keywords: Interrupted Time Series, ARIMAX, pulse functions, fertilizer subsidy.