Quand un et un ne font plus deux: calcul d'échelles d'équivalence intra-familiales au moyen d'un modèle collectif

In this paper, we present a collective model with public consumption. It is based on the more general model of Lewbel, Chiappori and Browning (2001). Rather than estimating a consumption technology, which captures all economies of scale of living in a couple, we determine a priori which goods are privately and which goods are publicly consumed. The collective model is completely identified by assuming that preferences over private and public goods are the same for singles and individuals in couples. The model allows calculating intra-household based equivalence scales, which meet the objections against traditional equivalence scales. It is applied to consumption data from a recent Belgian budget survey.