Assessment of Structural Change in Iranian Municipal Consumer's Preference for Edible Vegetable Oil

Edible vegetable oil has a special place in Iranian's family diet and considers as an important source of energy for supplying 45 to 50 percent of individuals required calories. Evaluating Iranian's consumers preference stability for edible vegetable oil commodity basket which is include liquid and solid vegetable oils, play an important role in determining production and trade programming framework. Present study determined stability or structural change in Iranian municipal consumer's preference for edible vegetable oil commodity basket using nonparametric approach of WARP and combining it with statistical test of K-W. WARP matrix results revealed that Iranian municipal consumer's preference violation occurs in 1996, 1998 and 2001. Also, applying K-W test showed that WARP violations in mentioned years caused by temporary nonlinear shocks and not due to structural change in Iranian municipal consumer's preference for edible vegetable oil commodity basket.