In this paper, Engel and Rothbarth functions of food and adult good expenditures are estimated (respectively) for a sample of households in Argentina surveyed by the National Household Expenditure Survey 2004/2005. By means of these functions, the aim is to study the existing relationship between household income and the proportion assigned to each type of good, the existence of scale economies in household consumption and the economic cost of children. By differentiating household income by strata, results are consistent with the theoretical model proposed by Barten (1964).