1. Short-Run Exchange Rate Determination
Issues in Global Trade & Finance
Prof. Bryson

2. Part I Factors Determining Rates

3. Short-run Exchange Rate Determination
In the Short Run,
the price of foreign exchange rises when
1. The foreign interest rate rises relative to ours. Why might this be?
(Mobile, investment funds follow the higher rates. As they change countries, they bid up currency values.)

4. Short-run Exchange Rate Determination
The price of foreign exchange also rises when
2. The expected future spot exchange rate rises. How come?
(If you expect you will have to pay more for the Euros you will need later because you expect the Euro/Dollar rate to rise, why not buy now before it does? Thus, the increased demand for Euros will bid the price up now.)

5. How It Works
Normally, returns on domestic and foreign government bonds tend to equality. Why?
Differences cause investors to reposition their portfolios, affecting exchange and interest rates.
Currency rates will rise when people buy in order to invest in foreign, short-term funds.

6. Determining Factors in Foreign Exchange Prices
The role of expectations is extremely important in forecasting the future. Lacking other information, what is the universal law of forecasting?
We extrapolate recent change into the future. Lacking other information, the future will look like the present.
The bandwagon effect.

7. Determining Factors in Foreign Exchange Prices
Once expectations are positive and buying goes on, we can begin a process of destabilizing speculation.
Friedman and bad speculation (buying high and selling low).
Bad currency speculation can lead to overshooting, where speculation may go in the right direction, but move past the equilibrium point.

8. Determining Factors in Foreign Exchange Prices
Expectations can be based on various kind of news on, e.g.,
policies,
trade data or performance,
international political tensions and situations.

9. Determining Factors in Foreign Exchange Prices
An increase in money supply
drives the interest rates down at first,
then prices begin to rise (the “chasing dollars” thing, and
currency values are driven down in the long run.

10. Determining Factors in Foreign Exchange Prices
When movements in exchange rates are not explainable as a function of the economic situation, they are referred to as speculative bubbles.

11. Markets, Exchange, and Interest Rates
Investing abroad has two steps.
First, get the exchange (DM, F, €, ¥, £) P$ P€
Sell Dollars (P$ declines) Buy Euros (P€ increases).
Second, invest in foreign government bonds at high i rates
Buy European (high i) bonds. Their price rises, (i falls). P
S1 S2 P
Sell US (low i) bonds, their p falls (i rises).
D D2

12. Part II. Short-term Rates and Investment Options

13. Short-term Investment Options
Should we pursue higher interest rates abroad? Check out the options
1. Invest at .05 (= ius) for 90 days (annual yield divided by four) in the U.S. at (1 + ius)
$1 million invested = $1,050,000 in 90 days.

14. SHORT-TERM INVESTMENT OPTIONS
2. Invest at .08 for 1 year in the U.K.
A. Buy £s in spot market at 1/ rs.
B. Invest at ( )/ rs
C. At the time of the investment, hedge the investment by selling contracted earnings in the forward market at rf .

15. SHORT-TERM INVESTMENT OPTIONS
When we hedge the investment by selling contracted earnings in the forward market,
the yield is ( iuk ) ( rf / rs )
$1,080,000 (0.61/0.63) = 1,080,000 (.97) = $1,045,714

16. Hot Money Investments Where we have
$1,080,000 (0.61/0.63) = 1,080,000 (.97) = $1,045,714,
if the future rate ($1.65) is greater than the spot rate ($1.63), one expects $ depreciation.

17. Hot Money Investments
The covered interest differential between the two investments is the yield from the (presumably higher) foreign investment minus the yield from the domestic investment.
It is:
CD = ( iuk ) ( rf / rs ) - (1 + ius)
$1,045, $1,050,000

18. Hot Money Investments 3. Invest at .08 in UK.
A. Buy £s in spot market at 1/ rs.
B. Invest at ( )/ rs
C. Do not hedge, but speculate.
Wait for the investment to pay out, take the yield and at that point (in 90 days or a year) purchase dollars with the pounds earned.

19. Hot Money Investments
If the £ goes up (or the value of the dollar vis-à-vis the pound declines, i.e., r’s > rs , ($3/£ > $2/£ ), we make more money.
But if the dollar appreciates, the £ will buy back fewer dollars at the end of the investment period.

20. More Generally, Uses of the Future
Change earnings in 90 days at r’s
Future $ Change earnings forward (covered) Future £
Invest in UK
Invest in U.S.
Borrow in UK
Borrow or
sell assets
in U.S.
Present
US Current $ currencies Current £ UK

21. Part III. Exchange Rates in the Long Run

22. Purchasing Power Parity: Money and Exchange Rates in the Long Run
The money supply determines the rate of inflation, which impacts the value of a currency. What is the impact?
Why must an inflating currency depreciate in value (or be devalued)?

23. Purchasing Power Parity: Money and Exchange Rates in the Long Run
Demand for a currency will decline if the commodities it will purchase are continually increasing in price.
Currency demand = f(transactions demands).

24. Purchasing Power Parity: Money and Exchange Rates in the Long Run
People must hold money balances to make purchases. In general, Md for a particular national currency shows that holding money is like “holding tickets for the GNP.”
Md = f (national GDP/yr).

25. Money and Exchange Rates in the Long Run
The Quantity Theory of Money
The Cambridge or Marshallian Quantity Theory
M = k (P) (y) y = real national or domestic product
Mf = kf ( Pf ) (yf) k = behavioral ratio
(coefficient) related to velocity
f = foreign
M = Money Supply
P = Price level

26. Money and Exchange Rates in the Long Run
The Quantity Theory of Money
In M = k (P) (y) and Mf = kf ( Pf ) (yf)
If k and kf are fixed, these quantity equations determine domestic and foreign price levels, the price ratio between national money and national product.

27. Price levels and exchange rates
Internationally traded goods will have similar price movements when measured in the same currency through trade’s arbitrage effect.

28. Price levels and exchange rates
– non-traded goods (e.g.,
those with large transport
costs will not necessarily
converge in price terms.

29. Price levels and exchange rates connected by Purchasing Power Parity
P = rs ( Pf )
where rs = exchange rate,
or, rewriting rs = P/ Pf,
We saw above that M = k (P) (y),
and solving for P, P = M/ky. So
substitute M/ky for P and we have
rs = [M/( k y)]
[Mf/(kf yf )]

30. Exchange rates and Purchasing Power Parity
The nation with slower Ms growth and faster expansion of productive capacity, should have a currency rising in value.
Rapid Ms growth and slow capacity expansion would lead to a depreciating currency.

31. Exchange rates and Purchasing Power Parity
This theory has proved empirically reliable for the long run only. For the short run, this is not a good predictor. Expectations and speculative movements affect the short run and non-traded goods also have an impact.

32. Interest Rates and Foreign Exchange
Foreign investors want to take advantage of high interest rates only if the real rates are high.
They will not want to hold foreign assets, and the spot rate of currencies will not be bid up, if real returns are not available because only nominal interest rates are high.

33. Interest Rates and Foreign Exchange
If interest rates rise merely because prices are increasing as the money supply expands, the currency value must decline.
The real interest rate is the nominal rate minus the rate of inflation.
Real rate = nominal rate - inflation.
Example: 5% = % %.

34. Hopper on “What Determines the Exchange Rate?”
A fundamental belief: “exchange rates are affected by fundamental economic forces, such as money supplies, interest rates, real output levels, or the trade balance.”

35. Hopper on “What Determines the Exchange Rate?”
But these fundamentals don’t affect the exchange rate in the short run.
The best forecast of the exchange rate, at least in the short run, is whatever it happens to be today.

36. Hopper on “What Determines the Exchange Rate?”
“The monetary model fails empirically except perhaps in unusual periods such as hyperinflations.” (p. 251)
After it was apparent that the model couldn’t be substantiated, economists tried to develop other ideas.

37. Hopper on “What Determines the Exchange Rate?”
Hopper discusses attempts to extend the monetary model – Dornbusches overshooting model, the portfolio balance model. Not much empirical support for these ideas has been found.
Econometricians found that a naïve strategy of using today’s exchange rate as a forecast works at least as well as any of the statistical models.

38. Hopper on “What Determines the Exchange Rate?”
Hopper concludes that “if we look backward or forward over periods of up to a year, the fundamentals don’t seem to explain the exchange rate, contrary to what standard models in international finance textbooks imply…perhaps economists will discover a model that works in the future.” (p. 253)

39. Hopper on “What Determines the Exchange Rate?”
The alternative view is that exchange rates are determined, at least in the short run (under two years) by market sentiment. Market participants take the fundamentals very seriously when forming exchange-rate expectations. Economists are just starting to build models of market sentiment.

40. Hopper on “What Determines the Exchange Rate?”
The exchange rates are determined in the long run by fundamentals. The empirical models do better here.
Long-term market forces, the fundamentals, tend gradually to outweigh short-term irrational or unpredictable speculative forces in exchange markets.