1. Chapter 8 Relationships among Inflation, Interest Rates, and Exchange Rates
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

2. Chapter Objectives
To explain the purchasing power parity (PPP) and international Fisher effect (IFE) theories, and their implications for exchange rate changes.
To compare the PPP, IFE, and interest rate parity (IRP) theories.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

3. Purchasing Power Parity (PPP)
When a country’s inflation rate rises relative to that of another country, decreased exports and increased imports depress the high-inflation country’s currency.
Purchasing power parity (PPP) theory attempts to quantify this inflation—exchange rate relationship.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

4. Interpretations of PPP
The absolute form of PPP is an extension of the law of one price. It suggests that the prices of the same products in different countries should be equal when measured in a common currency.
The relative form of PPP accounts for market imperfections like transportation costs, tariffs, and quotas. It states that the rate of price changes should be similar.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

5. Rationale behind PPP Theory
Suppose U.K. inflation > U.S. inflation.
 U.K. imports from U.S. and  U.K. exports to U.S.
Upward pressure is placed on the $ .
This shift in consumption and the $’s appreciation will continue against the £ until
in the U.K.: priceUS goods  priceUK goods
in the U.S.: priceUK goods  priceUS goods
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

6. Prices and Exchange Rates
A primary principle of competitive markets is that prices will equalize across markets if frictions (transportation costs) do not exist.
Comparing prices then, would require only a conversion from one currency to the other:
P$ x S = P¥
Where the product price in US dollars is (P$), the spot exchange rate is (S) and the price in Yen is (P¥).

7. Prices and Exchange Rates
If the law of one price were true for all goods and services, the purchasing power parity (PPP) exchange rate could be found from any individual set of prices.
By comparing the prices of identical products denominated in different currencies, we could determine the “real” or PPP exchange rate that should exist if markets were efficient.
This is the absolute version of the PPP theory.

8. Prices and Exchange Rates
If the assumptions of the absolute version of the PPP theory are relaxed a bit more, we observe what is termed relative purchasing power parity .
It is now argued that PPP is not particularly helpful in determining what the spot rate is today, but that the relative change in prices between two countries over a period of time determines the change in the exchange rate over that period.

9. Prices and Exchange Rates
More specifically, with regard to the relative form of PPP:
“If the spot exchange rate between two countries starts in equilibrium, any change in the differential rate of inflation between them tends to be offset over the long run by an equal but opposite change in the spot exchange rate.”

10. Been to Mc Donalds lately ?

11. The Big Mac Index
The Big Mac Index is based on the theory of purchasing-power parity (PPP), which says that exchange rates should move to make the price of a basket of goods the same in each country. Our basket contains just a single item, a Big Mac hamburger, but one that is sold around the world. The exchange rate that leaves a Big Mac costing the same in dollars everywhere is our fair-value yardstick.

13. The Hamburger Standard
A Big Mac costs approx. NOK 43 in Norway and $4.33 in the US
Spotrate at the same time NOK 6,09/$
Price of Big Mac in Norway measured in $ then equals 43/6,09 = $7,06
PPP exchange rate is 43/4,33 = NOK 9,93/$
The NOK is overvalued by approx. (9,93 – 6,09)/6,09 = 0,63 or 63 %

17. Derivation of PPP (1) Assume that PPP holds.
Over time, inflation occurs and the exchange rate adjusts to maintain PPP:
Ph  Ph (1 + Ih )
where Ph = home country’s price index
Ih = home country’s inflation rate
Pf  Pf (1 + If ) (1 + ef )
where Pf = foreign country’s price index
If = foreign country’s inflation rate
ef = foreign currency’s % D in value
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

18. Derivation of PPP (2) PPP holds  Ph = Pf and
Ph (1 + Ih ) = Pf (1 + If ) (1 + ef )
Solving for ef : ef = (1 + Ih ) – 1
(1 + If )
Ih > If  ef > 0 i.e. foreign currency appreciates
Ih < If  ef < 0 i.e. foreign currency depreciates
Example: Suppose IUK = 9% and IUS = 5% .
Then eUS = ( ) – 1 = 3.81%
( )
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

19. Simplified PPP Relationship
When the inflation differential is small, the PPP relationship can be simplified as ef  Ih – If
Example: Suppose IUK = 9% and IUS = 5% .
Then eUS  9 – 5 = 4%
U.K. consumers:  PUK = IUK = 9%
 PUS = IUS + eUS = 9%
U.S. consumers:  PUS = IUS = 5%
 PUK = IUK – eUS = 5%
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

20. Graphic Analysis of Purchasing Power Parity
Inflation Rate Differential (%)
home inflation rate—foreign inflation rate
% D in the foreign currency’s spot rate
- 2
- 4 2 4 1 3
- 1
- 3
PPP line
Increased purchasing power of foreign goods C A
Decreased purchasing power of foreign goods B D
International Financial Management, 2nd edition, Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

21. Testing the PPP Theory (1)
Conceptual Test
Plot actual inflation differentials and exchange rate % changes for two or more countries on a graph.
If the points deviate significantly from the PPP line over time, then PPP does not hold.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

22. Testing the PPP Theory (2)
Statistical Test
Apply regression analysis to historical exchange rates and inflation differentials:
ef = a0 + a1 [ (1+Ih)/(1+If) – 1 ] + m
Then apply t-tests to the regression coefficients. (Test for a0 = 0, and a1 = 1.)
If any coefficient differs significantly from what was expected, PPP does not hold.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

23. Testing the PPP Theory (3)
Empirical studies indicate that the relationship between inflation differentials and exchange rates is not perfect even in the long run.
However, the use of inflation differentials to forecast long-run movements in exchange rates is supported.
A limitation in the tests is that the choice of the base period will affect the result.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

24. Tests of PPP based on annual data from 1982 to 2004

25. Why PPP Does Not Occur PPP does not occur consistently due to:
confounding effects
Exchange rates are also affected by differences in inflation, interest rates, income levels, government controls and expectations of future rates.
a lack of substitutes for some traded goods
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

26. PPP in the Long Run
PPP can be tested by assessing a “real” exchange rate over time.
The real exchange rate is the actual exchange rate adjusted for inflationary effects in the two countries of concern.
If the real exchange rate follows a random walk, it cannot be viewed as being a constant in the long run. Then PPP does not hold.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

27. International Fisher Effect (IFE) (1)
According to the Fisher effect, nominal risk-free interest rates contain a real rate of return and anticipated inflation.
If all investors require the same real return, differentials in interest rates may be due to differentials in expected inflation.
Recall that PPP theory suggests that exchange rate movements are caused by inflation rate differentials.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

28. International Fisher Effect (IFE) (2)
The international Fisher effect (IFE) theory suggests that currencies with higher interest rates will depreciate because the higher nominal rates reflect higher expected inflation.
Hence, investors hoping to capitalize on a higher foreign interest rate should earn a return no higher than what they would have earned domestically.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

29. International Fisher Effect (IFE) (3)
Return in
Home
Currency 5 8 13 %
Real
Return
Earned 2 %
Investors
Residing in
Japan
U.K.
Canada
Japan
U.K.
Canada
Attempt to
Invest in Ih 3 6 11 % If ef
– 3
– 8 3
– 5 8 5 % if 5 8 13 % Ih 3 6 11 %
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

30. Derivation of the IFE (1)
According to the IFE, E(rf ), the expected effective return on a foreign money market investment, should equal rh , the effective return on a domestic investment.
rf = (1 + if ) (1 + ef ) – 1
if = interest rate in the foreign country
ef = % change in the foreign currency’s value
rh = ih = interest rate in the home country
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

31. Derivation of the IFE (2)
Setting rf = rh : (1 + if ) (1 + ef ) – 1 = ih
Solving for ef : ef = (1 + ih ) _ 1
(1 + if )
ih > if  ef > 0 i.e. foreign currency appreciates ih < if  ef < 0 i.e. foreign currency depreciates
Example: Suppose iUK = 11% and iUS = 12%
Then eUS = ( ) – 1 = –.89%
( )
This will make rf = rh
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

32. Derivation of the IFE (3)
When the interest rate differential is small, the IFE relationship can be simplified as
ef  ih _ if
If the British rate on 6-month deposits were 2% above the U.K. interest rate, the £ should depreciate by approximately 2% over 6 months. Then U.K. investors would earn about the same return on British deposits as they would on U.K. deposits.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

33. Graphic Analysis of the International Fisher Effect (1)
Interest Rate Differential (%)
home interest rate—foreign interest rate
% D in the foreign currency’s spot rate
- 2
- 4 2 4 1 3
- 1
- 3
IFE line
Lower returns from investing in foreign deposits C A
Higher returns from investing in foreign deposits B D
International Financial Management, 2nd edition, Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

34. Graphic Analysis of the IFE (2)
The point of the IFE theory is that if a firm periodically tries to capitalize on higher foreign interest rates, it will achieve a yield that is sometimes above and sometimes below the domestic yield.
On average, the yield achieved by the firm would be similar to that achieved by another firm that makes domestic deposits only.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

35. Tests of the IFE (1)
If actual interest rates and exchange rate changes are plotted over time on a graph, we can see whether the points are evenly scattered on both sides of the IFE line.
Empirical studies indicate that the IFE theory holds during some time frames. However, there is also evidence that it does not hold consistently.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

36. Tests of the IFE (2) IFE line Interest Rate Differential (%) - 2 - 4 2
home interest rate – foreign interest rate
- 2
- 4 2 4 1 3
- 1
- 3
% D in the foreign currency’s spot rate
IFE line
International Financial Management, 2nd edition, Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

37. Tests of the IFE (3)
To test the IFE statistically, apply regression analysis to historical exchange rates and nominal interest rate differentials:
ef = a0 + a1 [ (1+ih)/(1+if) – 1 ] + m
Then apply t-tests to the regression coefficients. (Test for a0 = 0, and a1 = 1.)
IFE does not hold if any coefficient differs significantly from what was expected.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

38. Why the IFE Does Not Occur
Since the IFE is based on PPP, it will not hold when PPP does not hold.
In particular, if there are factors other than inflation that affect exchange rates, exchange rates may not adjust in accordance with the inflation differential.
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

39. Comparison of the IRP, PPP, and IFE Theories (1)
Forward Rate
Discount or Premium
Interest Rate
Differential
Interest Rate Parity
(IRP)
Fisher
Effect
International
Fisher Effect (IFE)
Exchange Rate
Expectations
Inflation Rate
Differential
Purchasing
Power Parity
(PPP)
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA

40. Comparison of the IRP, PPP, and IFE Theories (2)
Interest rate parity
Forward rate premium p
Interest rate differential ih – if
Purchasing power parity
%  in spot exchange rate ef
Inflation rate differential Ih – If
International Fisher effect
%  in spot exchange rate ef
Interest rate differential ih – if
International Financial Management, 2nd edition
Jeff Madura and Roland Fox
ISBN © 2011 Cengage Learning EMEA