Lectures on Monetary Policy, In‡ation and the Business Cycle
Monetary Policy and the Open Economy
by
Jordi Galí July 2007
Motivation The basic new Keynesian model for the closed economy - equilibrium dynamics: simple three-equation representation - ability to match much of the evidence on the e¤ects of monetary policy and technology shocks - monetary policy: optimality of in‡ation targeting How does the introduction of open economy elements a¤ect that analysis and prescriptions? Can a model with nominal rigidities account for the volatility of nominal and real exchage rates? What role should the exchange rate play in the design of policy? What is the optimal degree of exchange rate volatility?
Some References Kollmann (JIE 01): nominal and real exchange rates, SOE version of EHL, pricing to market, many shocks Chari et al. (RES 02): two country model, Taylor type contracts, MP shocks Benigno and Benigno (RES 03): one-period contracts, two country, conditions for optimality of price stability Svensson (JIE 00): not-fully-optimizing model, strict vs. ‡exible CPI in‡ation targeting Benigno (JIE 04): staggered, currency union, heterogeneity Galí and Monacelli (RES 05): staggered, small open economy, equivalence result, optimal policy. Monacelli (JMCB 05): staggered, GM with limited pass-through Benigno and Benigno (JME 06): staggered, two countries, optimal policy de Paoli (LSE dissertation): generalization of GM
A New Keynesian Model of a Small Open Economy (GM RES 05) Households max E0
1 X
Ct1
Nt1+'
1
1+'
t
t=0
!
subject to Z 1 Z 1Z 1 PH;t(j)CH;t(j) dj + Pi;t(j)Ci;t(j) dj di +EtfQt;t+1Dt+1g 0
0
Dt +WtNt +Tt
0
1
) CH;t1
Ct = (1 CH;t =
Z
1
+
1
1
CF;t1
1
1
1
1
CH;t(j) di
0
CF;t
Z
0
1
(Ci;t)
1
1
di
;
Ci;t
Z
0
1
Ci;t(j)
1
1
dj
Firms Yt(i) = At Nt(i) at =
a
at
1
+ "at
Additional assumptions: Law of one price (full pass-through) Complete asset markets (at the international level)
Equilibrium Dynamics in the SOE: A Canonical Representation H;t
=
yet = Etfe yt+1g
where
yet = yt ytn ytn = + at + rtn (1 (
+ ')
;
Et f 1
H;t+1 g
(it
Etf
yt a ) at +
(1 )+ ! 1+' ; +'
yet
+
H;t+1 g
( + ) Etf yt+1g ;
+ (1
!
+'
Role of openness: assuming high substitutability (high ; ) @ @
<0
;
rtn)
@ @
<0
)(
1)
Optimal Monetary Policy Background and Strategy A Special Case =
=
=1
Optimality of Flexible Price Equilibrium: (1
)(1
1
)=1
Implied Monetary Policy Objectives yt = ytn H;t
=0
for all t. Implementation it = rtn +
H;t
+
y
yet
Evaluation of Alternative Monetary Policy Regimes Welfare Losses (special case) 1
(1
W=
2
)X
t
t=0
h
2 H;t
+ (1 + ')
yet2
i
Average period losses V=
(1 2
) h
var(
H;t )
+ (1 + ') var(e yt )
i
Three Simple Rules Domestic in‡ation-based Taylor rule (DITR) it =
+
H;t
CPI in‡ation-based Taylor rule (CITR): it =
+
Exchange rate peg (PEG) et = 0 Impulse Responses and Welfare Evaluation
t
An Extension with Imperfect Pass-Through (Monacelli JIE 05) Setup as in GM, with rest of the world modelled as a single economy. Key Assumption: imports sold through retail …rms price at the dock: et + pF;t(j) staggered price setting by retailers =) in general, pF;t(j) 6= et + pF;t(j) Law of One Price Gap: F;t
et + pt
pF;t
Consistent with the evidence (Campa and Goldberg (REStat 05): partial pass-through in the short run full pass through in the long run (for most industries).
Imported Goods In‡ation: F;t
= Et f
F;t+1 g
+
F
H;t
= Et f
H;t+1 g
+
H
F;t
Domestic Goods In‡ation mc ct
=) impossibility of replicating ‡exible price allocation =) emergence of a policy trade-o¤ =) gains from commitment
