and the week t. This can indeed vary over time in the case of a birth or death of a household member. Since a new born baby will not consume fish in his first few months, we assume that food diversification (and hence consumption of seafoods) starts at one year of age, yielding a total sample of 8913 individuals for the 2001 panel. These household intake series are then decomposed into individual intake series using the model described in the next section. These individual intake series are then used as imputs of the KDEM. In this section, the decomposition model is described and compared to similar models described in the literature, namely Chesher (1997, 1998); Vasdekis and Trichopoulou (2000). Its estimation and some structure tests are then presented. Consider a household composed of n$_{h,t}$ members, each member having unobserved weekly intakes y$_{i,h,t}$ , with i = 1 , . . . , n$_{h,t}$, h = 1 , . . . , H , and t = 1 , . . . , T . The week t intake of a household h is simply the sum across household members of the individual weekly intakes, such as As detailed below, the individual weekly intake y$_{i,h,t}$ is assumed to depend on There are obviously several ways to model the individual intake under these assumptions and this choice leads to more or less simple estimation procedures. In Chesher (1997, 1998); 2 Statistical methodology 2.1 The decomposition model 2.1.1 General principle 7 • the age and gender of the individual via a function f, • some socioeconomic characteristics of the household, • time (seasonal variations). y$_{h,t}$ = n$_{h,t}$ ∑ i =1 y$_{i,h,t}$. (2.1)