EtbtR+1 = |
ACRPIbtR, |
R RR bt = mcn xt |
πR 1 πR K R1 , and ARPI ≡ | |||
1 — α(2a — 1) + ʌ' 1 + J1 |
α2 |
(2a— 1) — |
α J2 (1 + αJ1 ) |
J3 (1 + αJ1) |
0 | |
— (2a — 1) + J1J1 |
α(2a — 1) |
J2 J1 |
J3J1 |
0 | ||
0 |
0 |
0 |
1 |
0 | ||
Λι(2α-1) |
0 |
2(1-a)μ |
1+2(1-a)βμ |
0 | ||
_ Γ σ(2a-1)C . 4θa(1-a) Z1 - [ = + (2a-1) =J |
J4 |
0 |
0 |
1+ |
C+δ2(1-a) | |
where J1 = (1-Л2)22а-1), J2 = |
2(1 |
-a)μ -1)β , J3 = |
μ—β(2a-1)and J4 |
= ((21a-1)) KZ [1 + α4θa(1 — a)] + |
σα(2a — 1) K=. Now there are two predetermined variables KR and ΠR-1. Note that the
eigenvalue associated with the capital stock dynamics is the same regardless of the index
of inflation targeted. The Appendix proves the following:
Proposition 3 Suppose that monetary policy reacts to current-looking consumer price
inflation. Then for an active monetary policy (μ > 1), the necessary and sufficient con-
ditions for determinacy of the difference system are:
(Case I) a > 0.5 and at least one of (33) and (34) is satisfied;
(2β — l)Λ2 — Λι [Λ2 + α(1 — Λ2)(2a — 1)]
Λ2β2(l — a)
(33)
2(1
ʌ λ4
a) + Â2J
2(1 — a)(1 — β)μ + λ ^1 Л2)] — (1 + Λι)
Λ2
+ (1 — β) + μ [Λι — Λ4] + 2(1 — a)μβ + —— > 0;
Λ2
(34)
1 Γ . C 1
(Case II) 0.5 > a > 2—δ 1 — δ — = 2
and
Λ 2Λ-2(1 + β)[1 + 2μ(1 — a)] .,. 2α(1 — 2a) ,
1 < (1+ μ)[α(1 — 2a)(2 — Λ2) — Λ2] if 1 + α(1 — 2a) > 2,
(35)
and at least one of (33) and (34) is satisfied;
17