consumer prices as2 ,
Pt = χ-χ(1 - χ)χ-1
(P^χ (Pf) 1-χ.
(2)
The price index associated with the consumer goods produced at home is defined
as,
ptd =
0 pt (z)
1
■ 1 -θ
1-θdz
(3)
while the same index for imported goods is given by,
f
pt = εt
J0 pt*(z)
1
■ 1-θ
1-θdz
(4)
The Cobb-Douglas form of the aggregate utility function implies relative
shares of home and foreign goods in consumption given by, cd = χ-Pd ct, and
t Pt
cf = (1 — χ) Ptf ct. There are corresponding equations for the foreign economy,
Pt
where foreign variables are denoted by a ‘*’. If we assume that the government
allocates spending across goods in the same pattern as consumers then the
total demand for domestically produced goods for the purposes of domestic and
foreign public and private consumption are given by the sum of the following
demands,
cdt
cf*t
Pt d Pt
χ-tct, and, gdt = χ-tgt
ptd ptd
(1 — χ)Ptc*,and, gf*t = (1 — χ)Ptg*.
ptf ptf
(5)
There is an additional source of demand for domestically produced goods - we
assume that foreign firms utilise a bundle of domestically produced goods in pro-
duction, just as domestic firms employ a bundle of foreign produced goods in do-
θ
• θ-1 -I θ-1
R01 mmiizft*) d dz
mestic production. Accordingly, we define m(i)f * =
as
being the bundle of domestically produced products used in foreign production,
by foreign firm i. As this composite intermediate good possesses the same de-
gree of substitutability between goods as the government and consumers’ con-
sumption bundles, foreign firms, domestic consumers and foreign consumers will
2 This price index is derived by minimising the cost of purchasing a single unit of the
composite consumption bundle, ct . The Cobb-Douglas form of the utility function implies
that to minimise costs consumers will allocate spending across the home and foreign goods
in the following patter, Pfcf = yχχΡtdcd. Utilising the fact that ct = (cd}x (ʃŋ = 1
f Pd -χ
allows us to eliminate ct from this relationship and solve in terms of cd = f γ-χχ ptf ) ∙
f χ — 1
The consumer price level is then defined as, Pt = Pt (cd) χ + Ptd cd. Replacing cd in this
expression yields the consumer price index defined above.