The Effective factors on Food Demand: the Application of the Quadratic Almost Ideal Demand System with Age-Period-Cohort Variables

Few Studies have studied the role of generational change (cohort effect), as an important demographic variable, within demand system, whereas generational changes can impact on elasticities, expenditure share as well as expenditure level. Therefore, to examine the impact of the demographic variables in addition to the economic and social variables on purchase and consumption of the nine food groups, this study uses a censored Quadratic Almost Ideal Demand System (QAIDS) with age-period-cohort (APC) variables. For this purpose, the pooled data of 337151 urban households' and 330501 rural households' for years 1363-93 was used. The results show age (aging population), generational change and period shocks impact on both food adoption and food consumption.