One of the greatest arguments about food commodities markets in Nigeria is that some of the
markets are inefficient because trade flows are mostly regional based. This study examined the
extent and degree of integration amongst Yam tuber and Cowpeas markets in six states from the
six geopolitical zones of Nigeria from 2000 - 2018 using Johansen Co-integration, Granger
Causality, Vector error correction model and Variance Decomposition methodologies. We confirm
that the markets are integrated, and have various degrees of price leadership. The speed of
adjustment to equilibrium ranged from two months [Niger (β = -0.62, p<0.05)] to two years [Oyo
(β = -0.05, p<0.05)] in yam market; four months [Niger (β = -0.32, p<0.05)] and nine months [Oyo
(β = -0.12, p<0.01)] in the brown-cowpea market; and from nine months [Adamawa and Niger (β
= - 0.12, p<0.05)] to one year [Oyo (β = -0.09, p<0.01)] in the white-cowpea market. The price
shocks on the markets were found to be mainly due to specific market functioning. The implication
of the finding is that the markets, if supplemented with more open policy initiatives, can play a
more effective role in increasing productivity and income of both producers and marketers.
Adejobi, A. O. (2005). Cowpea marketing in Maiduguri, Borno State; Investigations on building
a food marketing policy evidence base in Nigeria; A research programme funded by the UK
Department for International Development, February, 2005.
Adeoye, I., Dontsop Nguezet, P., Badmus, M., & Amao, I., (2011), Price transmission and market
integration of Banana and Plantain in Oyo State, Nigeria. ARPN Journal of Agricultural &
Biological Science, 6(5), 18
Akinseye, U. O., (2011). “Agricultural Financing and Performance in Nigeria: A Case study of
the Agricultural Credit Guarantee Scheme (ACGS)”. Research report presented in partial
fulfilment of the requirements for the degree of Master of Development Finance at the University
Akpan, S. B., Udoh, E., & Udo, U. (2014). Monthly price analysis of Cowpea (Beans) and Maize
in Akwa Ibom State, Southern Nigeria; International Journal of Food and Agricultural
Economics, 2 (2), 65-86.
Bergh, K., Orozco, P., Gugerty, M., & Anderson, C., (2012). Yam value chain: Nigeria; Evans
School Policy Analysis Research (EPAR) brief No 207, December 17, 2012.
Debaniyu, F. (2013). Price integration of Cowpea retail markets in Niger State, Nigeria” Academic
Research International, 4 (3), 264–277
Esposti, R. & Listorti, G. (2011). Agricultural price transmission across space and commodities
during price bubbles". Proceeding of the International Congress of European Association of
Agricultural Economists (EAAE); Change and Uncertainty Challenges for Agriculture, Food and
Natural Resources, Zurich. Ag.econ.114338. August 30 – September 2.
Ewan, R., Nwuneli, N., Spencer, H., & Humphrey, J., (2014). Mapping Value Chains for Nutrient-
Dense Foods in Nigeria; Institute of Development Studies (IDS) England Evidence Report No 65,
Food and Agricultural Organisation (FAO) (2008): Markets, prices, food situation and prospects
for Benin, Niger and Nigeria, Based on CILSS/FAO/FEWSNET/SIMA/WFP. Joint market
assessment mission to Benin, Niger and Nigeria 6. https://www.fao.org/giews. Assessed October
Ikudayisi, A. & Salman, K. (2014) Spatial Integration of Maize Market in Nigeria – A Vector
Error Correction Model. International Journal of Food and Agricultural Economics ISSN 2147-
2 (3) 71-80
International Institute of Tropical Agriculture (IITA) (2013). Healthy yam seed production,
https://www.ard-europe.org February 2013. Assessed May, 2019
Johansen S., (1988). Statistical Analysis of Co-integration Vectors. Journal of Economic
Dynamics and Control 12: 231-254.
Kormawa, P. M., Chianu, J. N., and Manyong, V.M. 2002. Cowpea Demand and Supply Patterns
in West Africa: The Case of Nigeria; International Institute of Tropical Agriculture (IITA), Ibadan,
– 386 January.
Mishili, F., Musa Shehu, J., Marfo, S., Chergna, M., & Loewenberg-DeBoer, J. (2007). “Consumer
preferences for quality characteristics along the Cowpea value chain in Nigeria, Ghana and Mali”.
Working Paper #06-17 January 2007.
Moghaddasi, R., (2008). Price transmission in horticultural products markets, Case of Date and
Pistachio in Iran. International Conference on Applied Economics– ICOAE, 663-669.
NBS / LSMS (2012). LSMS – Integrated Surveys on Agriculture General Household Survey Panel
NISER (Nigerian Institute of Social and Economic Research, Ibadan) (2008), The Global
Food Crisis: Impact and Policy Implications in Nigeria; Research Report Submitted by
NISER to the National FADAMA Development Office, Abuja, February, 2008
Nyongo, L. (2013). Maize price differences and evidence of spatial integration in Malawi: The
case of selected markets. 6th International Conference of Agricultural Statistics (ICAS VI): Rio De
Janeiro, Brazil, 23-25 October.
Ojiako, I., Ezedinma, C., Okechukwu, R., & Tarawali, G. (2014). Spatial Integration and Price
Transmission in Selected Rural and Urban Markets for Cassava fresh roots in Nigeria. Journal
of Economics and Sustainable Development 5(17): 2222-2855
Okoh, R., & Egbon, P., (2005). The integration of Nigeria's rural and urban foodstuffs markets.
African Economic Research Consortiums (AERC) Research Paper 151, Nairobi.
Onubogu, O.H & Dipeolu, A. O. (2019). Agricultural Price Transmission across space and time:
the case of Cowpea and Yam markets in Nigeria. 2019 Sixth International Conference of African
Association of Agricultural Economists, Abuja, Nigeria; no 181. September 23-26
Onubogu, O. H. (2020). Price variability, Co-integration and Leadership in Nigerian Yam market.
South Eastern Journal of Research and Sustainable Development). March 3(1): 122 – 149
Vavra, P. and Goodwin, B. 2005. Analysis of Price Transmission along the Food Chain, OECD
Food, Agriculture and Fisheries Working Papers, No. 3.