a specific sociological group, with added emphasis on inter-household or spill-over ef-
fects. We distinguish between “first members” and “second members” of households.
With particular consumer characteristics, spill-overs are absent: The effects of a change
of bargaining power within a household are confined to that household. With differ-
ent consumer characteristics, spill-overs can occur exactly as described earlier. For
instance, a first member of a household benefits from an increase in own bargaining
power, but loses if ceteris paribus first members of other households gain more bargain-
ing power. In Section 6, we offer concluding remarks.
2 General Equilibrium Model
We consider a finite pure exchange economy. The main departure from the traditional
model is that a household can have several members, each with their own preferences.
Fixed Household Structure.
The population is divided into finitely many households h = 1, . . . , n, with n ≥ 2.
Each household h consists of finitely many members i = hm with m = 1, . . . , m(h),
m(h) ≥ 1. Put I = {hm : h = 1, . . . , n; m = 1, . . . , m(h)}, the finite population of
individuals to be considered.
Commodities, Endowments, and Individual Preferences.
The commodity space is IR' with ' ≥ 1. Household h is endowed with a commodity
bundle ωh ∈ IR', ωh > 0. The aggregate or social endowment is ω = hωh ωh. A generic
individual i = hm ∈ I has:
• consumption set Xi = IR+;
• preferences £ i on the allocation space X ≡ ∏j∙∈j Xj represented by a utility
function Ui : X -→ IR.
The consumption bundle of a generic individual i is denoted by xi. Let x = (xi), y =
(yi) denote generic elements of X. For h = 1, . . . , n, define Xh = Qmm(=h1) Xhm with
generic elements xh = (xh1, . . . , xhm(h)). If x ∈ X is an allocation, then for h = 1, . . . , n,
household consumption is given by xh = (xh1 , . . . , xhm(h) ) ∈ Xh.