Estimating Consumer Price Indices Through Engel Curve and Linear Expenditure System : An Exploratory Note

This paper proposes a method of estimating spatial bilateral price index numbers from cross-section consumer expenditure data on different items using Engel curve analysis. A simple technique is developed by which it is possible to find a method for estimating a set of consumer price index numbers for a group of consumer expenditure items (both goods and services) for which only expenditure data are available. The main assumption of this technique is that the Linear Expenditure System (LES) is the correct and actual description of the complete demand system of the particular population of which we are interested to find the price index. The usefulness of the procedure is that it overcomes the problem of data inadequacy, a problem that is still prevalent in various databases, especially in the developing countries and it is easy to implement. To illustrate the method, ICRISAT VDSA database (which is in the public domain) of consumer expenditure is used and the spatial consumer price index number for non-food group for four villages of Andhra Pradesh is calculated for four years with one particular village taken as the base. The main limitation of the method is that violation of LES assumption can lead to inconsistent results