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Socioeconomic characteristics and time dependency In the application, all the socioe- conomic characterics are categorical variables. Consider the Q categorical variables W ( q ) h,t , q = 1 , . . . , Q, with m$_{q}$ modalities, and fix the m th q modality as the reference modality, then the socioe- conomic effect term in (2.2) and (2.3) is 

<img src='content_image/308932.jpg'>

where γ$_{q,m}$ is the effect of the m th modality of the socioeconomic variable q. 

Similarly, time is only measured by weekly counts throughout the year so that the time effect in (2.2) and (2.3) is simply 

where α$_{τ}$ is the effect of week τ and τ$_{R}$ is the reference week. 

<img src='content_image/308933.jpg'>

Error specification The error at the individual level ε$_{i,h,t}$ is assumed to be Gaussian with zero mean, and the variance-covariance structure is such that 

• households are independent, i.e. ∀ i, i $^{′}$, t, t′ and ∀ h ̸ = h ′ 

<img src='content_image/308934.jpg'>

• members of the same household are dependent, that is for ∀ h, t and i ̸ = i $^{′}$, 

<img src='content_image/308935.jpg'>

where ρ measures the dependence between individuals within the same household. 

• there is no time dependence, that is ∀ i, i ′ and ∀ t ̸ = t ′ 

<img src='content_image/308936.jpg'>

