Agricultural Supply Response to Trade and Exchange Rate Reforms in Nigeria

Doctoral Thesis / Dissertation from the year 2017 in the subject Agrarian Studies, University of Ibadan (Department of Economics), course: Economics, language: English, abstract: The study was anchored on theories of production and supply response. A Nerlovian supply response model (1956) as modified by Karbasi and Tavana (2008) which captures the impact of trade and exchange rate reforms on agricultural commodities prices and outputs, and with acreage cultivated, labour and cost of agricultural machinery as control variables was explored. Major cash crops (cocoa, palm produce, palm kernel, groundnuts, rubber and cotton) and food (cassava, maize, yam and rice accounting for 28.0% of the 40.0% of staple food output) were purposively selected. Data were collected from the World Trade Organisation Trade Statistics, World Bank UN-COMTRADE statistics and World Development Indicators; Food and Agricultural Organisation Year Book Statistics and Agricultural Market Access Database; Central bank of Nigeriäs Statistical Bulletin and National Bureau of Statistics Annual Abstracts of Statistics. A Structural Vector Autoregression model was estimated via the generalized Impulse response functions and variance decomposition estimation techniques. All estimates were validated at p¿0.05.

Trade policy shifted from a restrictive regime in 1970 to a liberalized regime starting from1995. Exchange rate policy similarly moved from a fixed regime in 1970 to a managed/float regime from 1986 to 2013. These reforms had diverse significant effects on both the prices and outputs of all sampled agricultural commodities. Trade effect was positive for palm kernel, cotton, rubber and cassava, while negative for the others. The effects were permanent across the ten commodities, while the elasticities for all the commodities range between 0.002 and 0.05. Exchange rate effect was positive for palm kernel, cotton, maize and rice, while negative for the others. The effects were also permanent except for rubber which was transitory, while elasticities for the commodities range between 0.1 and 2.3. On aggregate, the cost of machinery was found to be negatively related to the commodities outputs. A percentage increase in the cost of machinery brings about a 15.0 percent decline in output. Land and labour were positively and negatively related to output, respectively. An additional acre of land cultivation increased aggregate supply by 31.1%, while an increase in the use of labour decreased output by 19.0%.
Trade and exchange rate reforms were critical in explaining the supply responses of sampled commodities, hence, the need for favourable and stable reforms.