dT
Hr1
Y α - Г)Рσ 1 (1 — σT' + 1-τ, (σ - P-‘(1 ^θ) ' ɑ2*1
Substituting (12.6)-(12.8) in (12.5) yields:
σP1-σ
+(1 -
LΘ*γ (1 -Ti )
+ σT1 — 1+T— (σ — 1)
(1-L)ΘTf
1-ti
Pσ-1 [σP *1-σT * — Y (1 — L)]
σ — γ) (σLP*1-σT* + γ(ΘΘ* — 1)(1 — L)L) = 0.
(12.9)
If both, tax rate and tariff, are chosen to optimize welfare (12.4) and (12.9)
must be solved simultaneously for Ti and TA:
TI,Opt
TA,Opt
σP *ι-σ t * — γ (1 — L) — γLΘ*
σ2P*1-σT* — γσ(1-L) — γLΘ*,
(12)
.
σ
Resubstituting φ and T from (3) and (7) and simplifying yields:
(1 — L) (Y(σ —1) + σ(1 — Y)(1 — tA))+Lθ* fσ(1 — Y)⅛+Y(σ — l)ɔ
Ti =-------------------------------------w---------f~t--------⅛ > 0,
(1 — L)σ (γ(σ — 1)+σ(1 — γ)(1 — t*))+Lθ* (^σσ(1 — γ)l-TA+γ(σ2 — 1)J
which is positive as long as γ < 1 < σ.
Optimal taxes and tariffs under coop., eqs. (14,15):
The partial derivatives of the the overall welfare (13) with respect to domestic
taxes and tariffs are given by:
L—-Y
dTι
— + γTP-1
dTι + y
dP
dTI
ι(1 — T*)1-γ P*-γT dw* _ 0
b(1 — Ta)1-γ P-γT*( dTι ,
(14.1)
L^W +Y(1—Y) (1 — T (1 — Ta)-i) + <1 — T*P*^T (1—L)dW*
dTA ' V (1 — Ta)1-γ P-yT*V ,drAA
0. (14.2)
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