Concentration in the North Eastern Nigeria’s Yam Market: A Gini Coefficient Analysis

  • VB Taru
  • H Lawal
Keywords: Lorenz Curve, Gini Coefficient Analysis, Yam, Nigeria


Policy formulation has failed to take cognizance of the fact that production and marketing constitute a continuum and that the absence of development in one retards progress in the other. The study analysed the concentration of yam markets in southern part of Adamawa and Taraba states. It specifically identified the degree of product differentiation, market information dissemination and determined the concentration of yam sellers in the markets. A total of 410 respondents comprising 210 retailers and 200 wholesalers were randomly sampled using simple random sampling techniques from six purposively selected yam markets namely, Ganye, Nadu and Tola markets in Adamawa State and Wukari, Sarkin-Kudu, and Chanchanjim markets, Taraba State. Descriptive statistics, Gini coefficient and Lorenz Curve were the analytical tools used. The common features used in yam differentiation were yam varieties and size or length and market information were majorly disseminated by means of personal contact (verbal message) and telephone (GSM). The Gini coefficient of 0.56 and 0.52 were obtained for wholesaling and retailing, respectively. The concentration of sales was high with high income inequality in yam wholesaling than retailing in the area. This difference could result from the differences in their access to ownership and control of physical marketing facilities, funds availability and market behaviour and conducts. The markets therefore exhibit features of imperfect markets of oligopolistic competition. To reduce high concentration and income inequality among sellers especially in wholesale business, funds, security and physical market facilities should be provided to the yam marketers in the area.

Key word: Lorenz Curve, Gini Coefficient Analysis, Yam, Nigeria.


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eISSN: 1119-7455