Analysis of Lorenz and Concentration Curves: A Flexible Approach

摘要

Lorenz and concentration curves are used to estimate expenditure elasticities and an expenditure inequality measure for nine major food groups. A generalized functional form which incorporates a flexible heteroskedastic error term is proposed and estimated. The proposed specification is shown to be uniformly superior to the modified Beta function suggested by Kakwani and Podder (1976). The results indicate that elasticities are not necessarily monotonic or constant across the spectrum. Expenditures on food-at-home groups were more equally distributed across the population than both income and food-away-from-home expenditures. Data from the Consumer Expenditure Diary Survey was used.