In this paper we deal with the question of which measures of economic well-being are adequate to identify those groups of households in the U.S. whose economic conditions justify public concern and assistance. We derive a utility based measure of economic well-being from the estimation of a complete set of consumer demand equations. The demand system is Lluch's Extended Linear Expenditure System (Lluch, 1973). Household characteristics are incorporated using the scaling method proposed by Barten (1966). Using the welfare indicator derived, we study the composition of the poorest part of the population, using data from the 1972–73 Consumer Expenditure Survey. We compare our results with those obtained using various other welfare indicators, including the official U.S. poverty line. We show that using different family composition adjustments significantly and systematically affects just who are considered to be at the bottom of the welfare distribution. We finally suggest that program designers therefore can improve their target efficiency by carefully selecting from among the acceptable indices of welfare when defining program eligibility.