Combining Spatial and Temporal Variations in Unit Values in the Estimation of Price elasticities and Application to Tunisian Households

This paper presents a methodology extension of Deaton's (1990) model for estimating price elasticities, by pooling data from several surveys to improve the inter-cluster variability of unit values which is one of the key elements used inthe derivation of these elasticities. Since the surveys cover a relatively long period, possible structural changes in consumption behaviour occurring over time are accounted for by postulating that certain response coefficients of the basic model vary from one survey to the other, which is empirically confirmed by the conclusions of various tests designed for this purpose.