Equilibrium relations in the coconut sector: an analysis of fresh nut, oil and desiccated coconut market in Sri Lanka for the period 1956-2017

Abstract

The objective of this paper is to assess the equilibrium relations in the fresh nut, oil and Desiccated Coconut (DC) market in Sri Lanka with special emphasis on determining the supply and demand elasticities. To achieve this objective, the Partial Equilibrium Model (PEM) previously adopted for the Sri Lankan coconut industry was reestimated using Seemingly Unrelated Regression (SUR) method. Annual data on prices, quantities and other supply and demand related data for the period 1956-2017 were used for the analysis. The PEM captures the linkages in both production and consumption between the three markets. The results revealed that estimations are consistent with previous studies except for the income variable in demand equations for both fresh and oil markets where only the latter is statistically significant with negative coefficient indicating that oil has become an inferior good. Both the own price elasticity of supply and demand of fresh nut and oil were statistically significant with comparatively lower magnitudes whereas it was significant and higher in the DC market. When compared with the previous studies, the findings of the present study revealed that the magnitudes of the supply and demand elasticities in all three coconut markets have changed over the past decade and implications of those changes are further observed in the changes of directions of supply and demand relationships. Therefore, the coconut market model may also be extended further by incorporating other important sub-sectors as well.

Keywords

• coconut, elasticity, partial equilibrium model, seemingly unrelated regression