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Simple New Keynesian Open Economy Model Lawrence J. Christiano

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Page 1: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Simple New Keynesian Open EconomyModel

Lawrence J. Christiano

Page 2: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Outline

• Standard Simple Closed Economy Model• Extend Model to Open Economy

— Equilibrium conditions— Indicate complications to bring the model to the data.— Similar in spirit to Rames I model(Adolfson-Laséen-Lindé-Villan) at Riksbank

• Brief Discussion of Introducing Financial Frictions

— Christiano-Trabandt-Walentin Model, Ramses II model.— Mihai Copaciu of Romanian Central Bank.

Page 3: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Households

• Problem:

max E0

Ât=0

bt

log Ct − exp (tt)

N1+jt

1+ j

!, tt = ltt−1

+ #tt

s.t. PtCt + Bt+1

≤ WtNt + Rt−1

Bt + Profits-taxest

• First order conditions ( ¯pt ≡ Pt/Pt−1

):

1

Ct= bEt

1

Ct+1

Rt¯pt+1

exp (tt)CtNjt =

WtPt

.

Page 4: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Production• Final good firms:

— maximize profits:

PtYt −Z

1

0

Pi,tYi,tdj,

subject to technology:

Yt =

$Z1

0

Y#−1

#i,t dj

% ##−1

.

— Foncs:

Yi,t = Yt

&Pt

Pi,t

'#

!

"cross price restrictions"z }| {

Pt =

&Z1

0

P(1−#)i,t di

' 1

1−#

Page 5: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Intermediate Good Producers• Demand curve for monopoly producer of Yi,t:

Yi,t = Yt

&PtPi,t

'#

.

• Production function:

Yi,t = exp (at)Ni,t, Dat = rDat−1

+ #at

• Competitive in labor market:— Wage rate, Wt, taken as given.— (Real) marginal cost of production:

st =(1− n) (1− y+ yRt)Wt/Pt

eat,

where— n is a government subsidy to firms.— y is fraction of input costs that must be financed in advance.

• Under flexible prices, optimizing monopolist sets price as amarkup, #/ (#− 1) , over marginal cost:

Pi,t =#

#− 1

Ptst.

Page 6: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Intermediate Good Producers• Demand curve for monopoly producer of Yi,t:

Yi,t = Yt

&PtPi,t

'#

.

• Production function:

Yi,t = exp (at)Ni,t, Dat = rDat−1

+ #at

• Competitive in labor market:— Wage rate, Wt, taken as given.— (Real) marginal cost of production:

st =(1− n) (1− y+ yRt)Wt/Pt

eat,

where— n is a government subsidy to firms.— y is fraction of input costs that must be financed in advance.

• Under flexible prices, optimizing monopolist sets price as amarkup, #/ (#− 1) , over marginal cost:

Pi,t =#

#− 1

Ptst.

Page 7: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Intermediate Good Producers

• Calvo price setting frictions

— with probability q cannot change price: Pi,t = Pi,t−1

— with probability 1− q set price optimally: Pi,t = ˜Pt.

• Price optimizers set price as a function of current and futuremarginal costs:

˜pt ≡˜PtPt=

KtFt

,

Kt =#

#− 1

st + bqEt ( ¯pt)# Kt+1

Ft = 1+ bqEt ( ¯pt+1

)#−1 Ft+1

.

Page 8: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Aggregate Price Restrictions

Pt =

&Z1

0

P(1−#)i,t di

' 1

1−#

=h(1− q) ˜P1−#

t + qP1−#t−1

i 1

1−#

! 1 =

"

(1− q) ˜p1−#t + q

&1

¯pt

'1−## 1

1−#

! ˜pt =

"1− q ( ¯pt)

#−1

1− q

# 1

1−#

Page 9: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Aggregate Output• Want an aggregate output expression, relating Yt to Nt and At.

• Consider

Y∗t =Z

1

0

Yi,tdi =Z

1

0

AtNi,tdi = AtNt.

• Note also

Y∗t =Z

1

0

Yi,tdi =Z

1

0

Yt

&PtPi,t

'#

di = YtP#t

Z1

0

P−#i,t di

= YtP#t (P

∗t )−#

,

say, where

P∗t =$Z

1

0

P−#i,t di

%−1

#

=h(1− q) ˜P−#

t + q0P∗t−1

1−#i−1

#

Page 10: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Aggregate Output• Then,

Yt = p∗t Y∗t = p∗t AtNt,

p∗t =

&P∗tPt

'#

=

"

(1− q) ˜p−#t + q

&P∗t−1

Pt

'−##−1

=

"

(1− q) ˜p−#t + q

&Pt−1

Pt

P∗t−1

Pt−1

'−##−1

=

"

(1− q) ˜p−#t + q

¯p#t

p∗t−1

#−1

=

2

4(1− q)

1− q ( ¯pt)

#−1

1− q

! −#1−#

+ q¯p#

tp∗t−1

3

5−1

Page 11: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Basic�&ORVHG�(FRQRP\�Model

• 5HVXOWV�IURP�FORVHG�HFRQRP\�PRGHO

– Household preferences:

H0

4X

w=0

�w{

Ãx (Fw)� exp (� w)

Q1+*w

1 + *

!> x (Fw) � logFw

– Aggregate resources and household intertemporal optimization:

\w = s�wDwQw> xf>w = �Hwxf>w+1Uw

�w+1

– Law of motion of price distortion:

s�w =

3

C(1� �)

Ã1� � (�w)

%�1

1� �

! %%�1

+��%ws�w�1

4

D�1

= (1)

2

Page 12: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Basic Model ...

– Equilibrium conditions associated with price setting:

1 +Hw�%�1w+1��Iw+1 = Iw (2)

Iw

�1� ��%�1w

1� �

¸ 11�%

= Nw (3)

%

%� 1

= intermediate good rm marginal costz }| {

(1� �w)

=ZwSwby household optimizationz }| {exp (� w)Q

*w

xf>w

1� # + #Uw

Dw+Hw���

%w+1Nw+1

= Nw (4)

3

Page 13: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Homogeneous Domestic Good

Final ConsumptionConsumption

ForeignForeignHomogeneous

good

IntermediateGood Producers

Exporters

Labor Market Foreign BuyersBuyers

Page 14: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy

• Outline– the equilibrium conditions of the open economy model

� system�jumps�from�6�equations�in�basic�model�to�16�equations�in�16variables!� additional variables:

rate of depreciation, exports, real foreign assets, terms of trade, real exchange rate, respectivelyz }| {vw> {w> d

iw > s

{w > tw >

price of domestic consumption (now, f is a composite of domestically produced goods and imports)z}|{sfw >

price of importsz}|{sp>fw >

consumption price in ationz}|{�fw >

reduced form object to (i) achieve technical objective, (ii) correct a fundamental failing of open economy modelsz}|{xw >

closed economy variablesz }| {Uw> �w> Qw> fw>Nw> Iw> s

�w =

4

Page 15: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

– computing the steady state

– the ‘uncovered interest parity puzzle’, and the role of xw in addressing thepuzzle.

– summary of the endogenous and exogenous variables of the model, as wellas the equations.

– several computational experiments to illustrate the properties of the model.

5

Page 16: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• ModiILcations�to�basic�model�to�create�open�economy

– unchanged:� household preferences� production of (domestic) homogeneous good, \w (= Dws

�wQw)

� three Calvo price friction equations

– changes:� household budget constraint includes opportunity to acquire foreignassets/liabilities.� intertemporal Euler equation changed as a reduced form accommodationof evidence on uncovered interest parity.� \w = Fw no longer true.� introduce exports, imports, current account.� exchange rate,

Vw = domestic currency price of one unit of foreign currency = domestic moneyforeign money =

6

Page 17: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Monetary policy: three approaches– Taylor rule

log

µUw

U

¶= �U log

µUw�1

U

¶+(1� �U)Hw[u� log

µ�fw+1�f

¶+u| log

µ|w+1|

¶]+%U>w>

(5)

where (could also add exchange rate, real exchange rate and other things):�¯f ~target�consumer�price�inIOation%U>w ~iid,�mean�zero�monetary�policy�shock�|w ~\w@Dw

Uw ~‘risk�free’�nominal�rate�of�interest– D�policy� that�solves�Ramsey�problem�with� the�followingpreferences:

Hw

4X

m=0

�m{³100

h�fw�

fw�1�

fw�2�

fw�3 � (�

fw)4i´2

+ �|

µ100 log

µ|w|

¶¶2

+�{U (400 [Uw �Uw�1])2 + �v

¡Vw � V

¢2}– straight Ramsey policy that maximizes domestic social welfare.

8

Page 18: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Household budget constraintVwD

iw+1 + SwFw +Ew+1

� EwUw�1 + Vw

hxw�1U

iw�1

iDiw +ZwQw + Wudqvihuv dqg surilwvw

• Domestic bondsEw ~beginning of period w stock of loansUw ~rate of return on bonds

• Foreign assetsDiw ~beginning-of-period w net stock of foreign assets(liabilities, if negative) held by domestic residents.xwU

iw ~rate of return on D

iw

xw ~premium on foreign asset returns, over foreign risk free rate, Uiw

9

Page 19: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• optimality of household foreign asset decision (verify this by solvingLagrangian)

utility cost of one unit of foreign currency=Vw units of domestic currency, which is Vw@S fw units of Fwz }| {

xf>wVw

S fw

= �Hw

conversion into utility unitsz }| {xf>w+1

×

quantity of domestic consumption goods that can be purchased from the payoff of one unit of foreign currencyz }| {

Vw+1

foreign currency payoff next period from one unit of foreign currency todayz }| {Ui

wxw

S fw+1

orVw

S fw Fw

= �HwVw+1U

iwxw

S fw+1Fw+1

or1

fw= �Hw

vw+1Uiwxw

�fw+1fw+1 exp ({dw+1)> vw �

Vw

Vw�1> fw =

Fw

Dw= (6)

10

Page 20: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Optimality of household domestic bond decision:

1

Sfw Fw

= �HwUw

S fw+1Fw+1

– after scaling:1

fw= �Hw

Uw

�fw+1fw+1 exp ({dw+1)= (7)

11

Page 21: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Final domestic consumption goods, Fw

– produced�by�representative,�competitive�ILrm�using:

Fw =

�(1� $f)

1�f

¡Fgw

¢(�f�1)�f + $

1�ff (F

pw )

(�f�1)�f

¸ �f�f�1

Fgw ~one-for-one transformation on domestic homogeneous output good, price Sw

Fpw ~imported good, with price S

p>fw

Fw ~ ILnal�consumption�good,�with�price,�S fw

�f ~elasticity of substitution between domestic and foreign goods.– ProI L W � P a x i m i z a t i o n � � l e a d s � � t o :

Fgw = (1� $f) (s

fw)�f Fw

Fpw = $f

µsfwsp>fw

¶�f

Fw=

sfw =h(1� $f) + $f (s

p>fw )

1��fi 11��f (8)

sfw �Sfw

S w> sp>f

w �Sp>fw

Sw

12

Page 22: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

– Fpw is�produced�by�competitive�ILrm,�which�converts�foreign�homogeneousoutput one-for-one into Fp

w =

� Setting price equal to marginal cost:

Sp>fw = VwS

iw

³1� #i + #iUi

w

´> S i

w ~foreign currency price of foreign good.or,

sp>fw =

Sfw

S fw

VwSiw

Sw

³1� #i + #iUi

w

´= sfw

real exchange rate�VwSiw

Sfwz}|{tw

³1� #i + #iUi

w

´=

(9)

– Consumption�good�inIOation:

�fw �Sfw

S fw�1=

Swsfw

Sw�1sfw�1= �w

"(1� $f) + $f (s

p>fw )

1��f

(1� $f) + $f

¡sp>fw�1¢1��f

# 11��f

= (10)

13

Page 23: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Exports,[w

– foreign demand for exports

[w =

ÃS{w

S iw

!��i\ iw = (s

{w )��i \ i

w (11)

\ iw ~foreign output, S

iw ~price of foreign good, S

{w ˜ price of export

– [w is produced one-for-one using the domestic homogeneous good by arepresentative, competitive producer. Equating price, VwS

{w > to marginal

cost: VwSw{= Sw (�

{Uw+ 1� �{) >where��{= 1 if�all�inputs�must�be ILnanced�in�advance.�Rewriting

tws{w s

fw = �{Uw + 1� �{> (12)

wherereal exchange ratez}|{

tw �VwS

iw

S fw

>

terms of tradez}|{s{w =

S{w

S iw

twtw�1

= vw�iw�fw> vw =

Vw

Vw�1= (13)

14

Page 24: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Clearing in domestic homogeneous goods market:

output of domestic homogeneous good, \w= uses of domestic homogeneous goods

=

goods used in production of nal consumption, Fwz}|{Fgw +

exportsz}|{[w +

governmentz}|{Jw

= (1� $f) (sfw)�f Fw +[w +Jw=

• Substituting out for \w:

Dws�wQw = (1� $f) (s

fw)�f Fw +[w +Jw>

or,s�wQw = (1� $f) (s

fw)�f fw + {w + jw> (14)

fw �Fw

Dw> {w �

[w

Dw> jw �

Jw

Dw=

15

Page 25: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• %DODQFH�RI�3D\PHQWV– equality of international demand and supply for currency:

currency owing out of the countryz }| {acquisition of new net foreign assets, in domestic currency unitsz }| {

VwDiw+1 + expenses on importsw

=

currency owing into the countryz }| {

receipts from exportsw +

receipts from existing stock of net foreign assetsz }| {VwU

iw�1xw�1D

iw >

– The pieces:

expenses on importsw = VwSiw

³1� #i + #iUi

w

´$f

µsfwsp>fw

¶�f

Fw

receipts from exportsw = VwS{w [w=

– %DODQFH�RI�SD\PHQWV:VwD

iw+1 + VwS

iw 1� #i + #iUi

w

´$f

µsfwsp>fw

¶�f

Fw = VwS{w [w + VwU

iw�1xw�1D

iw =

16

Page 26: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

– Divide�EDODQFH�RI�SD\PHQWV�by�SwDw :

VwDiw+1

SwDw+VwS

iw

Sw

³1� #i + #iUi

w

´$f

µsfwsp>fw

¶�f

fw =VwS

{w

Sw{w +

VwUiw�1xw�1D

iw

SwDw>

or, using (9):

diw + sp>fw $f

µsfwsp>fw

¶�f

fw = sfwtws{w {w +

vwUiw�1xw�1d

iw�1

�w exp ({dw)> (15)

where diw is ‘scaled real, domestic value of foreign assets’:

diw =VwD

iw+1

SwDw

17

Page 27: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• ‘Risk’ adjustments

xw = x³diw > U

iw > Uw> !w

´= (16)

exp³�!d

³diw � d

´� !v

³Ui

w �Uw �¡Ui �U

¢´+ !w

´

!d A 0> small and not important for dynamics!v A 0> important!w ~mean zero, iid.

• Discussion of !d.– !d A 0 implies (i) if d

iw A d> then return on foreign assets low and diw &; (ii)

if diw ? d> then return on foreign assets high and diw %– implication: !d A 0 is a force that drives diw $ d in steady state,independent of initial conditions.

– logic is same as reason why steady state stock of capital in neoclassicalgrowth model is unique, independent of initial conditions.

– in practice, !d is tiny, so that its only effect is to pin down diw in steady state

and not affect dynamics (see Schmitt-Grohe and Uribe).

18

Page 28: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Discussion of !w

– Captures, informally, the possibility that there is a shock to the requiredreturn on domestic assets. Perhaps this could be a crude stand-in for a‘sub-prime mortgage crisis’, because it implies that people require a higherreturn on domestic assets if they are to hold them.

• Discussion of !v=

– !v is�an�important�reduced�form�feature,�designed�to�correct�a IOaw�in�models�of�international ILnance.� It�represents�a�quick ILx f o r�t h e � problem,�not�a�substitute�for�a�longer-run�solution.

– to�better�explain�this,�it�is�convenient�to ILrst�solve�for�the�model’s�steady�state.

19

Page 29: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

• Steady state

– household�intertemporal�efILciency�conditions:

0 = Hw

"1

fw� �

vw+1Uiwxw

�fw+1fw+1 exp ({dw+1)

#> steady state: 1 = �

vUix

�f(17)

0 = Hw

�1

fw� �

1

fw+1

Uw

�fw+1 exp ({dw+1)

¸> steady state: 1 = �

U

�f(18)

– assumption about foreign households:

1 = �Ui

�i(19)

�iw �Siw

S iw�1

(exogenous)

20

Page 30: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

– Taylor rule:�f= �¯f (central�bank’s�inIOation�target). (20)

– from (10):�f = � �

Sw

Sw�1= (21)

– using price friction equilibrium conditions:

s� =1���%1��³

1��(�)%�1

1��

´ %%�1> (no distortion if � = 1> ) (22)

I =1

1� ���%�1> (don’t allow �%�1�� ? 1) (23)

N =%

%�1 (1� �) exp (� )Q*+1s� (1� # + #U)

1� ���%> (���% ? 1) (24)

N = I

�1� ��%�1

1� �

¸ 11�%

= (25)

21

Page 31: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

– other steady state conditions:

sf =h(1� $f) + $f (s

p>f)1��fi 11��f (26)

sp>f = sft¡1� #i + #iUi

¢(27)

ts{sf = �{U + 1� �{ (28)s�Q = (1� $f) (s

f)�f f + { + j (29)

di + sft¡1� #i + #iUi

¢$f

µsf

sp>f

¶�f

f = sfts{{ +vUixdi

�(30)

{ = (s{)��i |i (31)– 15 equations: (17)-(31), 15 unknowns:

sf> sp>f> t> s{> f> {> di> U>x> �>N> I> s�> �f> v

– for convenience, set exogenous variables, j> d,

j = �j|> d = �d|> where | = s�Q=

22

Page 32: Simple New Keynesian Open Economy Modelfaculty.wcas.northwestern.edu/.../open_economy... · Outline • Standard Simple Closed Economy Model • Extend Model to Open Economy — Equilibrium

Extension to Small Open Economy ...

– algorithm for solving for the steady state:� s�> I> N can be computed from (21), (22), (23) and (25).� solve (24) forQ=

� solvej = �js

�Q

di = d = �ds�Q=

� (18), (19) implyUi

�i=

U

�f(32)

� steady�state�depreciation,�v> can�be�computed�from�the�inIOationdifferential:

tw$ t implies (see (13)) v�i = �f=

� (17), (18) implyvUix = U> (33)

or after multiplication by �i and rearranging,Ui

�ix =

U

�f> so (see (32)) x = 1 and dw = d (see (16))

23

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Extension to Small Open Economy ...

– rest of the algorithm solves a single non-linear equation in a single unknown.– set

* = sft=

– use (27), (28), (26):

sp>f = *U�>�

s{ =U{

*>

sf =h(1� $f) + $f (s

p>f)1��fi 11��f

t =*

sf=

– solve the resource constraint, (29), for f in terms of { :

f =sfts{{ + vUidi

� � di

sft¡1� #i + #iUi

¢$f

³sf

sp>f

´�f =

24

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Extension to Small Open Economy ...

– use the latter to substitute out for f in the current account, (30):

di + sft¡1� #i + #iUi

¢$f

µsf

sp>f

¶�f sfts{{ + vUidi

� � di

sft¡1� #i + #iUi

¢$f

³sf

sp>f

´�f

= sfts{{ +vUidi

�>

which can be solved linearly for {=

– evaluate�(31)�and�adjust�*˜ until�it�is�satisILed.�In�practice,�we�set�*˜ = 1 and�used�(31)�to�de ne�|i =

25

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Extension to Small Open Economy ...

• Uncovered interest rate parity puzzle and xew

– subtract equations (17) and (18):

Hw

"Uw � vw+1U

iwxw

fw+1�fw+1 exp ({dw+1)

#= 0= (34)

– totally differentiate the object in square brackets, and evaluate in steadystate

gUw � vw+1U

iwxw

fw+1�fw+1 exp ({dw+1)=

gUw

f�f�1

f�f

hvUigxw + vgUi

w +Uigvw+1

i

�U� vUi

[f�f]2g [fw+1�

fw+1 exp ({dw+1)] >

so�that,�taking�into�account�(33),�(34)�is,�to�a�ILrst�approximation:

Uw = Hwvw+1 + Uiw + xw> {w = log ({w)� log ({) =

{w � {

{=

26

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Extension to Small Open Economy ...

– Note:

Uw = logUw � log (U) ' uw � logU> Uiw = logU

iw � log

¡Ui¢' uiw � logU

i

Uw � 1 + uw> Uiw � 1 + uiw >

so that:

uw � log (U) = logVw+1 � logVw � log v + uiw � logUi + xw=

It follows from:

log (U)� log v� logUi = log

µU

vUi

¶= 0>

thatuw = Hw logVw+1 � logVw + uiw + xw (35)

xw = logxw = �!d³diw � d

´� !v

³uiw � uw �

¡ui � u

¢´+ !w

which is our log-linear expansion of (34).

27

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Extension to Small Open Economy ...

– Uncovered Interest Parity (UIP)� Under UIP, xw � 0 and

uw A uiw $ there must be an anticipated depreciation (instantaneous appreciation) of thecurrency for people to be happy holding the existing stock of net foreign assets.

� Consider the standard ‘UIP regression’ (!d ' 0> !w = 0)> involving riskfree rate differentials:

logVw+1 � logVw = � + �³uw � uiw

´+ xw=

� Substitute out for logVw+1 � logVw from (35) and make use of thefact that a (rational expectations) forecast error is orthogonal to date winformation, to obtain:

� =fry

³logVw+1 � logVw> uw � uiw

´

ydu³uw � uiw

´ = 1� !v>

28

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Extension to Small Open Economy ...

� In data,

· � ' �=75> so UIP rejected (that’s the UIP puzzle)· !v = 1=75$ � = �0=75=

� VAR impulse responses by Eichenbaum and Evans (QJE, 1992)

· data: uw % after monetary policy shock$ logVw+m falls slowly form = 1> 2> 3> === .

· UIP puzzle: uw % and expected appreciation of the currency representsa double-boost to the return on domestic assets. On the face ofit,� it�appears� that� there� is�an� irresistible�proILt� � �o p p o r t u n i t y . � W h y � doesn’t�the�double-boost�to�domestic�returns�launch�an�avalanche�of�pressure� to�buy� the�domestic�currency?� In�standard�models,�this�pressure�produces�a�greater�instantaneous�appreciation�in�the�exchange�rate,�until�the�familiar�UIP�overshooting�result�emerges�-the�pressure�to�buy�the�currency�leads�to�such�a�large�appreciation,

29

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Extension to Small Open Economy ...

that expectations of depreciation emerge. In this way, UIP leads tothe counterfactual prediction that a higher uw will be followed (afteran instantaneous appreciation) by a period of time during which thecurrency depreciates.

· model’s resolution of the UIP puzzle: when uw % the return requiredfor people to hold domestic bonds rises. This is why the double-boostto�domestic�returns�does�not�create�an�appetite�to�buy�large�amounts�of�domestic�assets.�Possibly�this�is�a�reduced�form�way�to�capture�the�notion�that�increases�in�uw make�the�domestic�economy�more�risky.(However,�the�precise�mechanism�by�which�the�domestic�required�return�rises�-�earnings�on� foreign�assets�go�up�-�may�be�dif cult�to�interpret.� An�alternative�speciILcation�was�explored,�with�risk-premia�affecting�domestic�bonds,�but�this�resulted�in�indeterminacy�problems.)

30

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Extension to Small Open Economy ...

• Model dynamics– 16 equations: price setting, (1), (2),(3) and (4); monetary policy rule, (5);household intertemporal Euler equations (6), (7); relative price equations(13), (8), (9), (10), (12); aggregate resource condition, (14); current account,(15); risk term, (16); demand for exports (11).

– 16 endogenous variables: sfw> sp>fw > tw> Uw> �w> �

fw> s

{w > Qw> s

�w > d

iw > xw> vw> {w> fw>Nw> Iw=

– exogenous variables: Uiw > |

iw > !w> jw> %U>w> {dw> � w> �

iw =

for the purpose of numerical calculations, these were modeled asindependent scalar AR(1) processes.

– the model was solved in the manner described above:� compute the steady state using the formulas described above� log-linearize the 16 equations about steady state� solve the log-linearized system� these calculations were made easy by implementing them in Dynare.

31

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Extension to Small Open Economy ...

• Numerical examples• Parameter values:

foreign and domestic in ation samez }| {�f = �i = 1=005>

no nancial frictionsz }| {# = #i = �{ = 0>

small weight on diw in xwz }| {!d = 0=03 >

� = 1=03�1@4>

prices unchanged on average for 1 yearz }| {� = 3@4 >

1@* Frisch elasticityz }| {* = 1 >

modest elasticity of demand for domestic intermediate goodsz }| {% = 6 >

subsidy extinguishes monopoly power in labor marginz }| {1� �w =

%� 1%

>

elasticity of substitution between domestic and foreign inputs in producing nal consumptionz }| {�f = 5

roughly 60% of domestic nal consumption is composed of domestic contentz }| {$f = 0=4 >

share of j in |z }| {�j = 0=3 >

net foreign assets/yz }| {�d = 0 >

elasticity of demand for exports as function of relative price paid by foreignersz }| {�i = 1=5 >

monetary policy rule parametersz }| {�U = 0=9> u� = 1=5> u| = 0=15

32

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Extension to Small Open Economy ...

• iid shock, 0.01, to %U>w=– !v = 0 $after instantaneous appreciation, positive %U>w shock followed bydepreciation.

– for higher !v> shock followed by appreciation.– long run appreciation is increasing function of persistence of �U=

0 1 2 3 4 5 6 7Ŧ0.1

Ŧ0.09

Ŧ0.08

Ŧ0.07

Ŧ0.06

Ŧ0.05

Ŧ0.04

Ŧ0.03

Ŧ0.02

Ŧ0.01

0Response of log exchange rate to monetary policy shock

Is = 0

Is = 0.5

Is = 1.0

Is = 1.75

Is = 1.75, U

R = 0.8

33

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Extension to Small Open Economy ...

We now consider a monetary policy shock, %U>w = 0=01= According to (5),implies a four percentage point (at an annual rate) policy-induced jump in Uw=The dynamic effects are displayed in the following gure, for !v = 0> !v = 1=75=

0 10Ŧ0.1

Ŧ0.05

0log, homogeneous output

Is = 0

Is = 1.75

0 10Ŧ0.06

Ŧ0.04

Ŧ0.02

log, consumption

0 105

6

7

domestic risk free rate (APR)

0 10Ŧ0.1

Ŧ0.09

Ŧ0.08

Ŧ0.07

log level, exchange rate

0 10Ŧ0.1

Ŧ0.05

0log, hours worked

0 10

Ŧ20

Ŧ10

0

consumer price inflation (APR)

0 10

Ŧ0.03

Ŧ0.02

Ŧ0.01

0

log, real exchange rate

0 10Ŧ0.08

Ŧ0.06

Ŧ0.04

Ŧ0.02

real foreign assets

0 100

0.02

0.04

0.06log, terms of trade

0 10

Ŧ0.08Ŧ0.06Ŧ0.04Ŧ0.02

0

log, exports

response to monetary policy shock

0 10

0

0.02

0.04

0.06log, imports

Note: (i) appreciation smaller, though a more drawn out, when !v is big; (ii)smaller appreciation results in smaller drop in net exports, so less of a drop indemand, so less fall in output and in ation; (iii) smaller drop in net exports resultsin smaller drop in real foreign assets.

34

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Extension to Small Open Economy ...

Consider now a domestic economy risk premium shock, a jump in theinnovation to !w equal to 0.01.

0 100

0.02

0.04

0.06

log, homogeneous output

0 10

Ŧ5

0

5x 10

Ŧ3 log, consumption

0 10

5.2

5.4

5.6

5.8

domestic risk free rate (APR)

0 10

0.05

0.06

0.07

0.08

log level, exchange rate

0 100

0.02

0.04

0.06

log, hours worked

0 100

0.02

0.04

consumer price inflation (APR)

0 100

0.01

0.02

0.03

log, real exchange rate

0 10

0.1

0.15

0.2

real foreign assets

0 10Ŧ0.06

Ŧ0.04

Ŧ0.02

0

log, terms of trade

0 100

0.020.040.060.08

log, exports

response to country risk premium shock

0 10

Ŧ0.1

Ŧ0.05

0

log, imports

With the reduced interest in domestic assets, (i) the currency depreciates, (ii)net exports rise, (iii) hours and output rise, (iv) the upward pressure on costsassociated with higher output leads to a rise in prices.

35

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Extension to Small Open Economy ...

Next we consider a 0.01 innovation in log, government consumption, jw=

0 10

Ŧ1

0

1

x 10Ŧ3

log, homogeneous output

0 10

Ŧ2

Ŧ1.5

Ŧ1

x 10Ŧ3 log, consumption

0 10

4.92

4.93

4.94

4.95

domestic risk free rate (APR)

0 10

Ŧ6

Ŧ5.5

Ŧ5

Ŧ4.5

x 10Ŧ3

log level, exchange rate

0 10

Ŧ1

0

1x 10

Ŧ3 log, hours worked

0 10

Ŧ2Ŧ1.5Ŧ1

Ŧ0.5

x 10Ŧ3

consumer price inflation (APR)

0 10

Ŧ15

Ŧ10

Ŧ5

0x 10

Ŧ4log, real exchange rate

0 10

Ŧ7Ŧ6Ŧ5Ŧ4Ŧ3

x 10Ŧ3

real foreign assets

0 100

1

2

3x 10

Ŧ3log, terms of trade

0 10

Ŧ4

Ŧ2

0x 10

Ŧ3log, exports

response to government consumption shock

0 10

0123

x 10Ŧ3

log, imports

After a delay, the higher jw leads to a rise in output. However, there is so muchcrowding out in the short run that output actually falls. There is crowding out ofnet exports and consumption because of the effects created by a higher interestrate. The higher interest rate directly reduces consumption, and by makingthe currency appreciate, it produces a fall in net exports. The initial drop ingovernment spending in the wake of a rise in government spending is interesting.

36

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Lawrence Christiano
Model with Capital, Richer Import Sector and Price Frictions that Slow Down Exchange Rate Pass-Through (CTW)
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Lawrence Christiano
Financial Frictions as the BGG or CMR in the Open Economy Model
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Question Confronting Many Emerging Market Economies

• At  some  point,  the  Fed  will  implement  its  ‘exit  strategy’  and  raise  US  interest rates (300-350 basis points?).

• In the past, when Fed raised rates sharply (e.g., 1982 Volcker disinflation, 1994 run-up in interest rates), hit the rest of world like a brick:

• Chilean crisis of 1982, Mexican default of August 1982. Mexican crisis of 1994.

• Will  the  US  ‘exit  strategy’  inflict  financial  crises  around  the  world,  especially in emerging market economies?

• Last  summer’s  ‘taper  episode’  makes  people  worry  about  this  possibility.

• I’ll  call  the  above  possibility  the  BIS  scenario.

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BIS Scenario

• Low  US  interest  rates  since  2008  have  encouraged  ‘excessive’  accumulation of debt in the world.

• This has particularly affected emerging market economies in Asia and Latin America.

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From: Jaime Caruana, General Manager, BIS,  ‘Debt, global liquidity and the challenges of exit’,  speech  in  Cartagena, Colombia, 8 July 2013.

Levels low relative to US, but still they grew to levels equal or greater than what they were in previous crises.

Not a huge problem

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Currency Mismatch Problem May Be Understated(Hyun  Shin,  ‘The  Second  Phase  of  Global  Liquidity…’,  November,  2013)

• Many emerging market borrowers issue dollar-denominated debt through foreign subsidiaries (say in the UK).

• By the usual definition (based on the residence of the issuer), the bonds are a liability of the UK entity.

• But,  it’s  the  consolidated  balance  sheet  that  matters  to  the  emerging  market firm.

• So, the debt issued via a foreign subsidiary could make the emerging market firm vulnerable to currency mismatch problems.

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• Hyun Shin argues:

• Amount of dollar denominated debt from emerging market firms may be greatly understated.

• This is suggested by evidence that foreign currency debt by nationality can be much larger than foreign debt by the usual residency definition.

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• Shin conjectures that distinction between external debt according to nationality  and  residence  helps  to  resolve  the  ‘taper’  puzzle:

• convulsions in emerging markets during taper episode last summer seem inconsistent with apparently small net external debt position (measured in residence terms) of firms in emerging markets.

• Less surprising if external debt position is in fact much bigger.

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BIS Scenario

• US raises interest rates.• Emerging market exchange rates depreciate.• Financial health of emerging market firms compromised.• They  cut  back  on  investment  activity….recessions  start.• Runs on emerging market banks known to be have made loans to

now-questionable emerging market non-financial firms.• And  so  on…

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Locomotive Scenario• Previous episodes of US interest rate hikes may be playing too big a

role in the pessimistic outlook.

• The circumstances in which the US raises interest rates may make a difference.

• Some previous episodes in which US raised rates were designed to fight inflation, not a response to strong US economy.

• In present circumstances, Fed has (credibly, I think) committed to only raise rates until well after the US economy has returned to health.

• Under these circumstances, interest rate hikes occur when the US is firmly in the position of a locomotive, pulling the rest of the world economy forward in its wake.

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Which Will it Be: BIS or Locomotive Scenario?

• Need a model to think about this question.

• Build in the BIS-type factors that raise concerns about the world economy.

• Accurately capture the degree of foreign currency indebtedness of financial and non-financial firms (i.e., avoid the biases that Hyun is concerned about).

• Build in the nature of the constraints that cause firms to pull back when their net worth contracts with exchange rate depreciation.

• Build  in  the  ‘locomotive’  scenario:

• Carefully  model  ‘forward  guidance’  – Fed commitment to keep interest rates low even after the US economy has begun to strengthen.

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A Model• Mihai Copaciu (Romanian Central Bank)

• Constructs small open economy models in which investment is sustained by purchases of entrepreneurs, who earn their revenues in domestic currency units.

• Entrepreneurs need financing, and the amount of financing they can get is partially a function of their accumulated net worth.

• Some of the financing is obtained from abroad.

• When the currency depreciates, entrepreneurs that borrowed abroad make capital losses and their net worth suffers.

• They are forced to cut back on expenditures, so that investment crashes, bringing down the economy.

• Same model also contains the usual features that imply an expansion in the US acts as a locomotive on the rest of the world.

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Mihai Copaciu’s Model of Currency Mismatch(Banca Naţională  a  României)

Typical smallopen economy

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Mihai Copaciu’s Model of Currency Mismatch(Banca Naţională  a  României)

Typical smallopen economy

Entrepreneurssupply capital

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DSGE Models Can Play a Useful Role in Discussions about  Fed  `Exit  Strategy’

• New Keynesian Open Economy Models can Capture Various Sides:

• Potential for US take-off to:• be a locomotive.• cause a loss of net worth by foreign firms/financial institutions and force a cut-back in

foreign  investment  (‘BIS  scenario’).

• Two aspects of the BIS scenario –• Hyun Shin has drawn attention to measurement problems.• Modeling: there are straightforward ways to get collateral constraints into

models.