© 2016 Worth Publishers, all rights reserved
The Open Economy Revisited:
The Mundell-Fleming Model and
the Exchange-Rate Regime
13CHAPTER
IN THIS CHAPTER, YOU WILL LEARN:
§ the Mundell-Fleming model
(IS-LM for the small open economy)
§ causes and effects of interest rate differentials
§ arguments for fixed vs. floating exchange rates
§ how to derive the aggregate demand curve for a
small open economy
1
2CHAPTER 13 The Open Economy Revisited
The Mundell-Fleming model
§ Key assumption:
Small open economy with perfect capital mobility.
r = r*
§ Goods market equilibrium—the IS* curve:
( ) ( ) ( )*Y C Y T I r G NX e= - + + +
where
e = nominal exchange rate
= foreign currency per unit domestic currency
3CHAPTER 13 The Open Economy Revisited
The IS* curve: goods market equilibrium
The IS* curve is drawn
for a given value of r*.
Intuition for the slope:
Y
e
IS*
( ) ( ) ( )*Y C Y T I r G NX e= - + + +
e NX Y¯ Þ ­ Þ ­
4CHAPTER 13 The Open Economy Revisited
The LM* curve: money market equilibrium
The LM* curve:
§ is drawn for a given
value of r*.
§ is vertical because
given r*, there is
only one value of Y
that equates money
demand with supply,
regardless of e.
Y
e LM*
( , )*M P L r Y=
5CHAPTER 13 The Open Economy Revisited
Equilibrium in the Mundell-Fleming model
Y
e LM*
( , )*M P L r Y=
IS*
( ) ( ) ( )*Y C Y T I r G NX e= - + + +
equilibrium
income
equilibrium
exchange
rate
6CHAPTER 13 The Open Economy Revisited
Floating & fixed exchange rates
§ In a system of floating exchange rates,
e is allowed to fluctuate in response to changing
economic conditions.
§ In contrast, under fixed exchange rates,
the central bank trades domestic for foreign
currency at a predetermined price.
§ Next, policy analysis:
§ in a floating exchange rate system
§ in a fixed exchange rate system
7CHAPTER 13 The Open Economy Revisited
Fiscal policy under floating exchange rates
Y
e
( , )*M P L r Y=
( ) ( ) ( )*Y C Y T I r G NX e= - + + +
Y1
e1
1
*LM
1
*IS
2
*IS
e2
At any given value of e,
a fiscal expansion
increases Y,
shifting IS* to the right.
Results:
Δe > 0, ΔY = 0
8CHAPTER 13 The Open Economy Revisited
Lessons about fiscal policy
§ In a small open economy with perfect capital
mobility, fiscal policy cannot affect real GDP.
§ Crowding out
§ closed economy:
Fiscal policy crowds out investment by causing
the interest rate to rise.
§ small open economy:
Fiscal policy crowds out net exports by causing
the exchange rate to appreciate.
9CHAPTER 13 The Open Economy Revisited
Monetary policy under floating exchange
rates
Y
e
e1
Y1
1
*LM
1
*IS
Y2
2
*LM
e2
An increase in M
shifts LM* right
because Y must rise
to restore eq’m in
the money market.
Results:
Δe < 0, ΔY > 0
( , )*M P L r Y=
( ) ( ) ( )*Y C Y T I r G NX e= - + + +
10CHAPTER 13 The Open Economy Revisited
Lessons about monetary policy
§ Monetary policy affects output by affecting
the components of aggregate demand:
closed economy: hM g ir g hI g hY
small open economy: hM g ie g hNX g hY
§ Expansionary mon. policy does not raise world
agg. demand, it merely shifts demand from foreign
to domestic products.
So, the increases in domestic income and
employment are at the expense of losses abroad.
11CHAPTER 13 The Open Economy Revisited
Trade policy under floating exchange rates
Y
e
e1
Y1
1
*LM
1
*IS
2
*IS
e2
At any given value of e,
a tariff or quota reduces
imports, increases NX,
and shifts IS* to the right.
Results:
Δe > 0, ΔY = 0
( , )*M P L r Y=
( ) ( ) ( )*Y C Y T I r G NX e= - + + +
12CHAPTER 13 The Open Economy Revisited
Lessons about trade policy
§ Import restrictions cannot reduce a trade deficit.
§ Even though NX is unchanged, there is less
trade:
§ The trade restriction reduces imports.
§ The exchange rate appreciation reduces
exports.
§ Less trade means fewer “gains from trade.”
13CHAPTER 13 The Open Economy Revisited
Lessons about trade policy, cont.
§ Import restrictions on specific products save jobs
in the domestic industries that produce those
products but destroy jobs in export-producing
sectors.
§ Hence, import restrictions fail to increase total
employment.
§ Also, import restrictions create sectoral shifts,
which cause frictional unemployment.
14CHAPTER 13 The Open Economy Revisited
Fixed exchange rates
§ Under fixed exchange rates, the central bank
stands ready to buy or sell the domestic currency
for foreign currency at a predetermined rate.
§ In the Mundell-Fleming model, the central bank
shifts the LM* curve as required to keep e at its
preannounced rate.
§ This system fixes the nominal exchange rate.
In the long run, when prices are flexible,
the real exchange rate can move even if the
nominal rate is fixed.
15CHAPTER 13 The Open Economy Revisited
Fiscal policy under fixed exchange rates
Y
e
Y1
e1
1
*LM
1
*IS
2
*IS
Under floating rates,
a fiscal expansion
would raise e.
Results:
Δe = 0, ΔY > 0
Y2
2
*LM
To keep e from rising,
the central bank must
sell domestic currency,
which increases M
and shifts LM* right.
nder floating rates,
fiscal policy is i effective
at changing output.
Under fixed rates,
fiscal policy is very
effective at changing
output.
16CHAPTER 13 The Open Economy Revisited
Monetary policy under fixed exchange rates
2
*LM
An increase in M would
shift LM* right and reduce e.
Y
e
Y1
1
*LM
1
*IS
e1
To prevent the fall in e,
the central bank must
buy domestic currency,
which reduces M and
shifts LM* back left.
Results:
Δe = 0, ΔY = 0
Under float g rates,
monetary policy is
very effectiv t
changing output.
Under fixed rates,
monetary policy cannot
be used to affect output.
17CHAPTER 13 The Open Economy Revisited
Trade policy under fixed exchange rates
Y
e
Y1
e1
1
*LM
1
*IS
2
*IS
A restriction on imports
puts upward pressure on e.
Results:
Δe = 0, ΔY > 0 Y2
2
*LM
To keep e from rising,
the central bank must
sell domestic currency,
which increases M
and shifts LM* right.
Under floating rates,
impor restrictions
do not affect Y or NX.
Under fixed rates,
import restrictions
increase Y and NX.
But, these gains come
at the expense of other
countries: the policy
merely shifts demand from
foreign to domestic goods.
18CHAPTER 13 The Open Economy Revisited
Summary of policy effects in the
Mundell-Fleming model
type of exchange rate regime:
floating fixed
impact on:
Policy Y e NX Y e NX
fiscal expansion 0 h i h 0 0
mon. expansion h i h 0 0 0
import restriction 0 h 0 h 0 h
19CHAPTER 13 The Open Economy Revisited
Interest-rate differentials
Two reasons why r may differ from r*
§ country risk:
The risk that the country’s borrowers will default
on their loan repayments because of political or
economic turmoil.
Lenders require a higher interest rate to
compensate them for this risk.
§ expected exchange rate changes:
If a country’s exchange rate is expected to fall,
then its borrowers must pay a higher interest rate
to compensate lenders for the expected currency
depreciation.
20CHAPTER 13 The Open Economy Revisited
Differentials in the M-F model
where θ (Greek letter “theta”) is a risk premium,
assumed exogenous.
Substitute the expression for r into the
IS* and LM* equations:
( , )*M P L r Y= +q
( ) ( ) ( )*Y C Y T I r G NX e= - + + + +q
*r r q= +
21CHAPTER 13 The Open Economy Revisited
The effects of an increase in θ
2
*LM
IS* shifts left, because
hθ g hr g iI
Y
e
Y1
e1
1
*LM
1
*IS
LM* shifts right, because
hθ g hr g i(M/P)d,
so Y must rise to restore
money market eq’m.
Results:
Δe < 0, ΔY > 0
2
*IS
e2
Y2
22CHAPTER 13 The Open Economy Revisited
§ The fall in e is intuitive:
An increase in country risk or an expected
depreciation makes holding the country’s currency
less attractive.
Note: An expected depreciation is a
self-fulfilling prophecy.
§ The increase in Y occurs because
the boost in NX (from the depreciation)
is greater than the fall in I (from the rise in r).
The effects of an increase in θ
23CHAPTER 13 The Open Economy Revisited
Why income may not rise
§ The central bank may try to prevent the
depreciation by reducing the money supply.
§ The depreciation might boost the price of
imports enough to increase the price level
(which would reduce the real money supply).
§ Consumers might respond to the increased risk
by holding more money.
Each of the above would shift LM* leftward.
24CHAPTER 13 The Open Economy Revisited
CASE STUDY:
The Mexican peso crisis
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25
30
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7/10/94 8/29/94 10/18/94 12/7/94 1/26/95 3/17/95 5/6/95
U.
S.
C
en
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p
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M
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ic
an
P
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25CHAPTER 13 The Open Economy Revisited
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20
25
30
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7/10/94 8/29/94 10/18/94 12/7/94 1/26/95 3/17/95 5/6/95
U.
S.
C
en
ts
p
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M
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an
P
es
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CASE STUDY:
The Mexican peso crisis
26CHAPTER 13 The Open Economy Revisited
The Peso crisis didn’t just hurt Mexico
§ U.S. goods became expensive to Mexicans, so:
§ U.S. firms lost revenue
§ Hundreds of bankruptcies along
U.S.-Mexican border
§ Mexican assets lost value (measured in dollars)
§ Reduced wealth of millions of U.S. citizens
27CHAPTER 13 The Open Economy Revisited
Understanding the crisis
§ In the early 1990s, Mexico was an attractive place
for foreign investment.
§ During 1994, political developments caused an
increase in Mexico’s risk premium (θ):
§ peasant uprising in Chiapas
§ assassination of leading presidential candidate
§ Another factor:
The Federal Reserve raised U.S. interest rates
several times during 1994 to prevent U.S. inflation.
(Δr* > 0)
28CHAPTER 13 The Open Economy Revisited
Understanding the crisis
§ These events put downward pressure on the
peso.
§ Mexico’s central bank had repeatedly promised
foreign investors it would not allow the peso’s
value to fall,
so it bought pesos and sold dollars to
prop up the peso exchange rate.
§ Doing this requires that Mexico’s central bank
have adequate reserves of dollars.
Did it?
29CHAPTER 13 The Open Economy Revisited
Dollar reserves of Mexico’s central bank
December 1993 ……………… $28 billion
August 17, 1994 ……………… $17 billion
December 1, 1994 …………… $ 9 billion
December 15, 1994 ………… $ 7 billion
During 1994, Mexico’s central bank hid the
fact that its reserves were being depleted.
30CHAPTER 13 The Open Economy Revisited
M the disaster M
§ Dec. 20: Mexico devalues the peso by 13%
(fixes e at 25 cents instead of 29 cents)
§ Investors are SHOCKED! – they had no idea
Mexico was running out of reserves.
§ hθ, investors dump their Mexican assets and
pull their capital out of Mexico.
§ Dec. 22: central bank’s reserves nearly gone.
It abandons the fixed rate and lets e float.
§ In a week, e falls another 30%.
31CHAPTER 13 The Open Economy Revisited
The rescue package
§ 1995: U.S. & IMF set up $50b line of credit to
provide loan guarantees to Mexico’s govt.
§ This helped restore confidence in Mexico,
reduced the risk premium.
§ After a hard recession in 1995, Mexico began a
strong recovery from the crisis.
32CHAPTER 13 The Open Economy Revisited
CASE STUDY:
The Southeast Asian crisis 1997–98
§ Problems in the banking system eroded
international confidence in SE Asian economies.
§ Risk premiums and interest rates rose.
§ Stock prices fell as foreign investors sold assets
and pulled their capital out.
§ Falling stock prices reduced the value of collateral
used for bank loans, increasing default rates,
which exacerbated the crisis.
§ Capital outflows depressed exchange rates.
Data on the SE Asian crisis
exchange rate
% change from
7/97 to 1/98
stock market
% change from
7/97 to 1/98
nominal GDP
% change
1997–98
Indonesia −59.4 −32.6 −16.2
Japan −12.0 −18.2 −4.3
Malaysia −36.4 −43.8 −6.8
Singapore −15.6 −36.0 −0.1
S. Korea −47.5 −21.9 −7.3
Taiwan −14.6 −19.7 n.a.
Thailand −48.3 −25.6 −1.2
U.S. n.a. 2.7 2.3
34CHAPTER 13 The Open Economy Revisited
Floating vs. fixed exchange rates
Argument for floating rates:
§ allow monetary policy to be used to pursue other
goals (stable growth, low inflation).
Arguments for fixed rates:
§ avoid uncertainty and volatility, making
international transactions easier.
§ discipline monetary policy to prevent excessive
money growth & hyperinflation.
35CHAPTER 13 The Open Economy Revisited
The Impossible Trinity
A nation cannot have free
capital flows, independent
monetary policy, and a
fixed exchange rate
simultaneously.
A nation must choose
one side of this
triangle and
give up the
opposite
corner.
Free capital
flows
Independent
monetary
policy
Fixed
exchange
rate
Option 1
(U.S.)
Option 3
(China)
Option 2
(Hong Kong)
36CHAPTER 13 The Open Economy Revisited
CASE STUDY:
The Chinese Currency Controversy
§ 1995–2005: China fixed its exchange rate at
8.28 yuan per dollar and restricted capital flows.
§ Many observers believed the yuan was significantly
undervalued. U.S. producers complained the cheap
yuan gave Chinese producers an unfair advantage.
§ President Bush called on China to let its currency
float; others wanted tariffs on Chinese goods.
§ July 2005: China began to allow gradual changes
in the yuan/dollar rate. By June 2013, the yuan had
appreciated 35 percent.
37CHAPTER 13 The Open Economy Revisited
Mundell-Fleming and the AD curve
§ So far in M-F model, P has been fixed.
§ Next: to derive the AD curve, consider the impact of
a change in P in the M-F model.
§ We now write the M-F equations as:
(Earlier in this chapter, P was fixed, so we
could write NX as a function of e instead of ε.)
( ) ( , )*M P L r Y=LM*
( ) ( ) ( ) ( )*Y C Y T I r G NX ε= - + + +IS*
38CHAPTER 13 The Open Economy Revisited
Y1Y2
Deriving the AD curve
Y
ε
Y
P
IS*
LM*(P1)LM*(P2)
AD
P1
P2
Y2 Y1
ε2
ε1
Why AD curve has
negative slope:
hP
g LM shifts left
g hε
g iNX
g iY
g i(M/P)
39CHAPTER 13 The Open Economy Revisited
From the short run to the long run
LM*(P1)
ε1
ε2
then there is
downward pressure
on prices.
Over time, P will
move down, causing
(M/P) h
ε i
NX h
Y h
P1 SRAS1
1Y
1Y Y
ε
Y
P
IS*
AD
Y
Y
LRAS
LM*(P2)
P2 SRAS2
If ,Y Y<1
40CHAPTER 13 The Open Economy Revisited
Large: Between small and closed
§ Many countries—including the U.S.—are neither
closed nor small open economies.
§ A large open economy is between the polar
cases of closed and small open.
§ Consider a monetary expansion:
§ As in a closed economy,
hM g ir g hI (though not as much)
§ As in a small open economy,
hM g iε g hNX (though not as much)
C H A P T E R S U M M A R Y
1. Mundell-Fleming model:
§ the IS-LM model for a small open economy.
§ takes P as given.
§ can show how policies and shocks affect income
and the exchange rate.
2. Fiscal policy:
§ affects income under fixed exchange rates, but not
under floating exchange rates.
41
C H A P T E R S U M M A R Y
3. Monetary policy:
§ affects income under floating exchange rates.
§ under fixed exchange rates is not available to affect
output.
4. Interest rate differentials:
§ exist if investors require a risk premium to hold a
country’s assets.
§ An increase in this risk premium raises domestic
interest rates and causes the country’s exchange
rate to depreciate.
42
C H A P T E R S U M M A R Y
5. Fixed vs. floating exchange rates
§ Under floating rates, monetary policy is available
for purposes other than maintaining exchange rate
stability.
§ Fixed exchange rates reduce some of the
uncertainty in international transactions.
43