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Lecture 1b. The open economy. The international flows of capital and goods, balance of payments and exchange rates.
References: these slides have been developed based on the ones provided byBeatriz de Blas and Julián Moral (UAM), as well as the official materials fromMankiw, 2009 and Blanchard, 2007 books. I am grateful for that.
1
Carlos Llano (P)& Nuria Gallego (TA)
Learning objectives
• A model for the small open economy model.
– What makes it “small”
– How the trade balance and exchange rate are
determined
– How policies affect trade balance & exchange rate
2
Outline
1. The international flows of goods2. The international flows of capital3. Exchange rate determination:
1. Net balance2. Purchase Power Parity
3
0. PRELIMINARIES
4
How NX depends on ε
ε U.S. goods become more expensive relative to foreign goods
EX, IM
NX
5
Sterling’s Real Exchange Rate andTrade Deficit of the UK: 1980‐2005
90
100
110
120
130
140
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
Rea
l Effe
ctiv
e Ex
chan
ge R
ate
(avr
g.
2000
=100
)
-6
-5
-4
-3
-2
-1
0
1
2
3
Net Exports (%
of GD
P)
depreciationappreciation
6
The net exports function
• The net exports function reflects this inverse relationship between NX and ε :
NX = NX(ε)
7
The NX curve
0 NX
ε
NX(ε)
ε1
When ε is relatively low, home goods are relatively inexpensive
NX(ε1)
so net exports will be high
8
The NX curve
0 NX
ε
NX(ε)
ε2
At high enough values of ε, home goods become so expensive that
NX(ε2)
we export less than we import
9
Dynamic analysis: the J curve
Depreciation of your local currency
0
Net
Exp
orts
, NX
Time
CA
B
0
_
+
U.S. Net Exports and the Real Exchange Rate: 1980‐2005
80
90
100
110
120
130
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
Rea
l Effe
ctiv
e Ex
chan
ge R
ate
(avr
g. 2
000=
100)
-6
-5
-4
-3
-2
-1
0
Net Exports (%
of GD
P)
depreciation
appreciation
11
1. THE INTERNATIONAL FLOWS OF GOODS
12
1. The international flows of goods
• In an open economy (domestic) spending need not equal output
(domestic) savings need not equal investment
13
Preliminaries
EX = exports = foreign spending on domestic goods
IM = imports = C f + I f + G f
= spending on foreign goods
NX = net exports (a.k.a. the “trade balance”) = EX – IM
d fC C C d fI I I d fG G G
superscripts:d = spending on
domestic goodsf = spending on
foreign goods
14
GDP = expenditure on domestically produced g & s
d d dY C I G EX
( ) ( ) ( )f f fC C I I G G EX
( )f f fC I G EX C I G
C I G EX IM
C I G NX
15
GDP identity in an open economy
• New GDP identity for open economy
• Examples of why the new accounting entries are necessary to make the equality hold:– An imported Toyota truck is counted in C but not in GDP; the negative entry in IM cancels out the positive entry under C
– Exported Ford truck is counted in GDP but not in C, I or G domestically; the positive entry in EX provides a way to account for it on the right‐hand side of the equation.
Y C I G NX
16
The national income identity in an open economy
Y = C + I + G + NX
or, NX = Y – (C + I + G )
net exports
domestic spending
output
17
Trade surpluses and deficits
• trade surplus:If output > spending; exports > imports. Size of the trade surplus = NX
• trade deficit:If spending > output; imports > exports Size of the trade deficit = –NX
NX = X – IM = Y – (C + I + G )
18
We subtract C + T from both sides of the equation:
S = I + G ‐ T – IM/ε + X
Using the expression: NX X – IM/ε
Y = C + I + G – IM/ε + X ; S = Y ‐ C ‐ T
NX = S + (T ‐ G) ‐ I
Trade
balance
National
SavingsInvestments= ‐
Trade surpluses and deficits
U.S. net exports, 1950‐2006
U.S. Net Exports, 1950-2006
-800
-600
-400
-200
0
200
1950 1960 1970 1980 1990 2000
billi
ons
of d
olla
rs
-8%
-6%
-4%
-2%
0%
2%
perc
ent o
f GD
P
NX ($ billions) NX (% of GDP)
20
2. THE INTERNATIONAL FLOWS OF CAPITAL
21
International capital flows
• Net capital outflow= S – I= net outflow of “loanable funds”= net purchases of foreign assets
the country’s purchases of foreign assets minus foreign purchases of domestic assets
• When S > I, country is a net lender
• When S < I, country is a net borrower22
The link between trade & cap. flows
NX = Y – (C + I + G )implies
NX = (Y – C – G ) – I= S – Itrade balance = net capital outflow
Thus, a country with a trade deficit (NX < 0)
is a net borrower (S <I ).
Thus, a country with a trade deficit (NX < 0)
is a net borrower (S <I ).
23
Saving and Investment in a Small Open Economy
• An open‐economy version of the loanable funds model.
• Includes many of the same elements:
production function: ( , )Y Y F K L
consumption function: ( )C C Y T
investment function: ( )I I r
exogenous policy variables: ,G G T T
+TR-T)
24
National Saving: The Supply of Loanable Funds
r
S, I
National saving does not depend on the interest rate
( )S Y C Y T G
S
+TR-T)-G
25
Assumptions re: capital flows
a. domestic & foreign bonds are perfect substitutes (same risk, maturity, etc.)
b. perfect capital mobility:no restrictions on international trade in assets
c. economy is small:cannot affect the world interest rate, denoted r*
a & b imply r = r*
c implies r* is exogenous
a & b imply r = r*
c implies r* is exogenous
26
Investment: The Demand for Loanable Funds
Investment is still a downward‐sloping functionof the interest rate,
r*
but the exogenous world interest rate…
…determines thecountry’s level ofinvestment.
I (r* )
r
S, I
I (r )
27
If the economy were closed…
r
S, I
I (r )
S
rc
( )cI rS
…the interest rate would adjust to equate investment and saving:
28
But in a small open economy…
r
S, I
I (r )
S
rc
r*
I 1
the exogenous world interest rate determines investment…
…and the difference between saving and investment determines net capital outflows and net exports
NX
29
Three thought experiments
1. Fiscal policy at home
2. Fiscal policy abroad
3. An increase in investment demand
30
1. Fiscal policy at home
r
S, I
I (r )
1S
I 1
An increase in G,TR or decrease in Treduces saving.
1*r
NX1
2S
NX2
Results: 0I
0NX S
31
NX and Government Budgets in the U.S.: 1974‐2005
-6
-5
-4
-3
-2
-1
0
1
2
3
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
Gov
ernm
ent B
udge
t Sur
plus
(%
of G
DP)
-6
-5
-4
-3
-2
-1
0
1
2
3
Net Exports (%
of GD
P)
32
NX and Government Budgets in the U.S.: 1974‐2005
33
2. Fiscal policy abroad
r
S, I
I (r )
1SExpansionary fiscal policy abroad raises the world interest rate. 1
*rNX1
NX2
Results: 0I
0NX I
2*r
1( )*I r2( )*I r
34
3. An increase in investment demand
r
S, I
I (r )1
EXERCISE:Use the model to determine the impact of an increase in investment demand on NX, S, I, and net capital outflow.
NX1
*r
I 1
S
35
r
S, I
I (r )1
ANSWERS:I > 0,S = 0,net capital outflows and net exports fall by the amount I
NX2
NX1
*r
I 1 I 2
S
I (r )2
3. An increase in investment demand
36
3. EXCHANGE RATE DETERMINATION:3.1. NET BALANCE
37
How ε is determined
• The accounting identity says NX = S – I• We saw earlier how S – I is determined: S depends on domestic factors (output, fiscal policy variables, etc.) I is determined by the world interest rate r*
• So, ε must adjust to ensure
NX(ε) = S – I(r*)
38
How ε is determined
Neither S nor Idepend on ε, so the net capital outflow curve is vertical.
Neither S nor Idepend on ε, so the net capital outflow curve is vertical.
ε
NX
NX(ε )
1 ( *)S I r
ε adjusts to equate NXwith net capital outflow, S I.
ε adjusts to equate NXwith net capital outflow, S I.
ε 1
NX1
39
Interpretation: Supply and demand in the foreign exchange market
demand: NXForeigners need “your local currency” in order to buy your products (exports).
demand: NXForeigners need “your local currency” in order to buy your products (exports).
ε
NX
NX(ε )
1 ( *)S I r
supply: S‐INet capital outflow (S I ) is the supply of dollars (local currency) to be invested abroad.
supply: S‐INet capital outflow (S I ) is the supply of dollars (local currency) to be invested abroad.
ε 1
NX 1
40
Next, four experiments:
1. Fiscal policy at home
2. Fiscal policy abroad
3. An increase in investment demand
4. Trade policy to restrict imports
41
1. Fiscal policy at home
A fiscal expansion reduces national saving, net capital outflow, and the supply of dollars (local currency in the U.S.) in the foreign exchange market…
A fiscal expansion reduces national saving, net capital outflow, and the supply of dollars (local currency in the U.S.) in the foreign exchange market…
…causing the real exchange rate to rise and NX to fall.
…causing the real exchange rate to rise and NX to fall.
ε
NX
NX(ε )
1 ( *)S I r
ε1
NX1NX2
2 ( *)S I r
ε2
42
2. Fiscal policy abroad
An increase in r*reduces investment, increasing net capital outflow and the supply of dollars in the foreign exchange market…
An increase in r*reduces investment, increasing net capital outflow and the supply of dollars in the foreign exchange market…
…causing the real exchange rate to fall and NX to rise.
…causing the real exchange rate to fall and NX to rise.
ε
NX
NX(ε )
1 1( *)S I r
NX1
ε1
21 ( )*S I r
ε2
NX2
43
3. Increase in investment demand
An increase in investment reduces net capital outflow and the supply of dollars (local currency in U.S.) in the foreign exchange market…
An increase in investment reduces net capital outflow and the supply of dollars (local currency in U.S.) in the foreign exchange market…
ε
NX
NX(ε )…causing the real exchange rate to rise and NX to fall.
…causing the real exchange rate to rise and NX to fall.
ε1
1 1S I
NX1
21S I
NX2
ε2
44
4. Trade policy to restrict imports
At any given value of ε, an import quota IM NX demand for
dollars shifts right
At any given value of ε, an import quota IM NX demand for
dollars shifts right
ε
NX
NX (ε )1
S I
NX1
ε1
NX (ε )2Trade policy doesn’t affect S or I , so capital flows and the supply of dollars remain fixed.
Trade policy doesn’t affect S or I , so capital flows and the supply of dollars remain fixed.
ε2
45
4. Trade policy to restrict imports
ε
NX
NX (ε )1
S I
NX1
ε1
NX (ε )2
Results:ε > 0 (demand increase)
NX = 0(supply fixed)
IM < 0 (policy)
EX < 0(rise in ε )
Results:ε > 0 (demand increase)
NX = 0(supply fixed)
IM < 0 (policy)
EX < 0(rise in ε )
ε2
46
The determinants of the nominal exchange rate
• Start with the expression for the real exchange rate:
e P
P *
Solve for the nominal exchange rate:
e P *
P
47
The determinants of the nominal exchange rate
• So e depends on the real exchange rate and the price levels at home and abroad…
…and we know how each of them is determined:
( * , )M L r YP
e P *
P
** *
* ( * *, )M L r YP
NX() = S - I(r*)
48
The determinants of the nominal exchange rate
• Rewrite this equation in growth rates
ee
P *
P *PP
*
For a given value of , the growth rate of e equals the difference between foreign and domestic inflation rates.
e P *
P
49
Inflation differentials and nominal exchange rates
Percentage changein nominalexchange rate
10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4
Inflation differential
Depreciationrelative to U.S. dollar
Appreciationrelative to U.S. dollar
-1-2-3 10 2 3 4 5 6 87
France
Canada
SwedenAustralia
UK
IrelandSpain
South Africa
Italy
New Zealand
NetherlandsGermany
Japan
Belgium
Switzerland
50
3.2. PURCHASE POWER PARITY (PPP)
51
Purchasing Power Parity (PPP)
• PPP: e P = P*
Cost of a basket of domestic goods, in foreign currency.
Cost of a basket of domestic goods, in domestic currency.
Cost of a basket of foreign goods, in foreign currency.
Solve for e : e = P*/ P
PPP implies that the nominal exchange rate between two countries equals the ratio of the countries’ price levels.
52
Purchasing Power Parity (PPP)
• If e = P*/P, then e
PP *
P *
P
PP *
1
and the NX curve is horizontal:
ε
NX
NXε = 1
S I Under PPP, changes in (S – I ) have no impact on ε or e.
Under PPP, changes in (S – I ) have no impact on ε or e.
53
NX
I
r
large open economy
small open economy
closedeconomy
A fiscal expansion in three models
falls, but not as much as in small open economy
fallsno
change
falls, but not as much as in closed economy
nochange
falls
rises, but not as much as in closed economy
nochange
rises
A fiscal expansion causes national saving to fall.The effects of this depend on openness & size:
January 201254