complete domestically and international equity trade is forbidden3. Moreover, in order
to pay for nominal expenses, cash in advance is needed. Under these assumptions, the
agent’s budget constraint is given by
Mj ≥ PCj = Wj Lj + Dj,
(4)
where Mj are individual j’s money balances, Wj is the nominal wage and Dj are agent
j,s dividends received by all domestic firms.
2.4 Demand side
The allocation of a representative individual’s demand across the Home- and Foreign-
produced brands yields
C Iz ∖-P ( Ph (3) V c -p Ри <г) V ( Ph Y ' C O1
Cjp(z) = ~Л~РЙ~) Cjp =I ⅛^J l"pj Cj, (5)
1 ( Pf(z) y-' ( Pf(z) ∖-λ ( Pf Y-1
Cj-F(z) = T—p ∖-pF^) c'1∙f =I p- TU Cj (6)
where Ри(z) and Pf(z) are the prices for a brand z charged by a domestic and foreign
firm at Home, respectively4. The law of one price is assumed to hold across all individual
brands, so that Pc(z) = P*(z), Vz ∈ [0,1], where asterisks denote Foreign values of
the corresponding Home variables, and c ∈ [H, F] . Moreover, because Home and Foreign
agents have identical preferences, the law of one price implies that purchasing power parity
must hold for the consumer price indexes:
P = P *.
Thus integrating the demand for a Home-produced brand (5) and Foreign-produced
brand (6) across all agents yields the total demand faced by a firm z:
..... ( . )■( P ),C. :„
where Cw ≡ 7C +(1 — 7)C is the total consumption in the world economy, C ≡ 1 fj Cj dj
is the per capita consumption of a Home agent and C* ≡ ɪ--^ ʃ, Cjdj is the per capita
consumption of a Foreign resident5.
3However, securities markets are redundant in this model so as current accounts always balance in
equilibrium (Obstfeld and Rogoff, 1998).
4Recall that λ > 1 captures the elasticity of substitution among varieties, while the elasticity of substi-
tution between the domestic and foreign good is equal to 1.
5Note that Cw is both per capita and total world consumption.