INDIVIDUAL VERSUS AGGREGATE INCOME ELASTICITIES FOR HETEROGENEOUS POPULATIONS
研究异质性人群中个体与总体收入弹性的差异，发现总体弹性不等于个体弹性均值，差异由人口异质性决定，并通过英国家庭支出调查数据用非参数方法估计，表明总体弹性高估了许多商品组的个体弹性均值。
SUMMARY This paper deals with different concepts of income elasticities of demand for a heterogeneous population and the relationship between individual and aggregate elasticities. In general, the aggregate elasticity is not equal to the mean of individual elasticities. The difference depends on the heterogeneity of the population and is quantified by a covariance term. Sign and magnitude of this term are determined by an empirical analysis based on the UK Family Expenditure Survey. It is shown that the relevant quantities can be identified from cross‐sectional data and, without imposing restrictive structural assumptions, can be estimated by nonparametric techniques. It turns out that the aggregate elasticity significantly overestimates the mean of individual elasticities for many commodity groups. Copyright © 2011 John Wiley & Sons, Ltd.