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Appendix A: Proof of Proposition 2
To verify the comparative statics of the system (4)-(5)-(7) with respect to s, let us
use the definitions where β =(n - 2)h(x) + h(z) and βH ≡ (n - 1)h(x) to rewrite
it in terms of the three unknown variables x, z and βH :
Π1 [x, h(z) - h(x)+βH, 0] = 0
Π1H[z,βH,s]=0 (19)
Π [x, h(z) - h(x)+βH, 0] = F
The second equation provides an implicit relationship z = z(βH, s) with dz/двн =
—ΠH>∕ΠH and ∂z∕∂s = — ΠH3∕ΠH > 0. Substituting this expression we obtain a
system of two equations in two unknowns, x and βH :
Π1 [x, h(z(βH, s)) — h(x) + βH , 0] = 0
Π [x, h(z(βH,s)) — h(x) + βH, 0] = F
Totally differentiating the system we have:
dx
dβH
∏ [1 + h0(z) ∂∂H] —П12 [1 + h0 (z) ∂∂h]
Π2h0(x) Π11 — Π12h0(x)
∏12h0(z) ∂S ds
Π2h0(z) ∂S ds
22