(c) r.d. weaver 2004 in the real world, do currencies matter? adding some reality

(c) R.D. Weaver 2004

In the real world, do currencies matter?

Adding some reality


Exchange rate as a price?

Exchange rates are the price of a currency

eus,Euro = $/€

eus,yen= $/¥

eus,pound=$/£


Exchange rate markets

Google “ FX” markets or FOREX markets

Today, foreign exchange markets are the representative of state-of-the-art information and trading technology, they operate 24/7


Let’s review – exchange rates and international product prices Sources for exchange rates?

Federal Reserve Bank is best source of historical series annual, monthly, weekly, daily are available.

Yahoo Finance and other sites also provide data series Hundreds of on-line sites provide current rates


Spatial arbitrage with differing currencies Buy product in country j in ¥

Sell product in country i in $ In the real world, you open a foreign exchange account,

convert $ to ¥ on a continuous basis. Why? Averaging effect

In some cases, Pepsi is former Soviet Union, you may not trust the value of the currency, it may not be convertible! So, choose a product (vodka) and ship it back home!

Same story with plastic toys and McDonald’s in ChinaIn other cases, buy property in the importing country (RCA

Building and Rockafellar Center, NYC !)


Different currencies trade of same product REVIEW

Define exchange rate with US as i Japan as j

Eji = units ith cur/ units jth cur ¥/$ Suppose we consider profits in

= Eji PeiYij - Pj Yij – Cij (Yij ) > 0

= (¥/$) * ($/box)*boxes - (¥/box)*boxes -¥cost

Arbitrage equilibrium if Eji Pe

i- Pj-C(Y)/Y = 0

Eij Pei = Pj + AC(Yi,j)

exch rates play a role


Implications Exchange Rates and Prices are bound together!

Suppose we simplify a bit……

Ejit Pit = Pjt + AC(Yi,j)

and suppose AC(Yi,j) ~ 0

then Ejit Pit = Pjt Ejit = Pjt / Pit = ¥/$

In spatial equilibrium, the prices across locations should reflect the exchange rate….


In fact, the exchange rate reflects relative purchasing power of the two currenciesSo what does this mean? Ejit = ¥/$= Pjt / Pit

The financial world uses this approach to estimate the true value of currencies…its called the real exchange rate, ejit

Official market Ejit = ¥/$= Pjt / Pit

= ejit real exchg rate


In fact, the exchange rate reflects relative purchasing power of the two currenciesIf Ejit = ¥/$= Pjt / Pit = ejit

If this holds, ejit the real exchange rate is a “barter price”

= [¥/bu soy in Tokyo]/ [$/bu soy in U.S.]

If soy is soy……..bushels cancel out and we have..

= ¥/$


In fact, the exchange rate reflects relative purchasing power of the two currencies

We call this rule Ejit = ¥/$= Pjt / Pit = ejit

The purchasing power parity rule, and the real exchange rate as the purchasing power parity value of the exchange rate…PPP for short


Definitions real vs official exchange ratesDefine the official exchange rate in the market as:

Ejit = ¥/$

Define the real exchange rate

ejit = ¥/$= Pjt / Pit

Why might these two exchange rates differ?


In fact,………. In the 70’s you could take jeans to Poland and sell them

for 300 times their value in the U.S.

You can still take advantage on many distortions of the purchasing power parity rule!

Google your favorite product in 5 countries, compute the PPP or “real” exchange rate and compare vs. official exchange rate!

Why does this happen?


If exchanges rates are regulated, what is the true value of a currency? Use PPP to compute the “real exchange rate” E Compare vs. the actual official exchange rate e

Economist BigMac index

Define a currency (e.g. ¥) as “overvalued” vs $ if E = ¥/$ > e “undervalued” vs $ if E < e

why??


Purchasing Power Parity

http://www.economist.com/markets/currency/


So, PPP column 3 tells you the true exchange rate

Column 4 is official

As we can see, many exchange rates are distorted.

Why?????

Can you circle the currencies that are undervalued vs. the dollar?


Exchange rate distortion

Define e as the PPP or real exchange rate,

E as official……..then

For China, we see eyuan/$ = 3.23 <<< E yuan/$ =7.60

$ is undervalued vs yuan = yuan is overvalued vs $


Why do governments distort their exchange rates?

Suppose

Ejit Pit = Pjt + AC(Yi,j)

then, trade flow is optimal at say Yij *

Suppose you would like to increase exports from jyou could advertise, you give tax credits for exporters

or, you could reduce the value of your currency, making your products cheaper for foreign buyers


Why distort your exchange rate?Suppose the real exchange rate is ejit

then if the official rate Eojit =ejit arbitrage would force

ejit Pit = Pit + AC(Yi,j)

then, trade flow is optimal at say Yij *

Suppose the government reduces the value of the yen, (undervalues it) making it cheaper so Ejit > Eo

jit = ejit more ¥/$! So,……

Ejit Pit > ejit Pit = Pjt + AC(Yi,j) (yen/$) $ = yen + yen cost

This means an exporter would earn more ¥ profits/unit shipped to the U.S. So……exports would increase!

Undervalued currency exports will increase (So why did the Bush Admin allow the dollar to lose value in 2007-2009? )


Why distort your exchange rate?Suppose Japan faced inflation, not enough supply relative to

demand……….they would like to increase imports, shut off exports….

They could increase the value of their currency, making it more expensive (overvalued) Ejit < ejit less ¥/$!

So,……

Ejit Pit < ejit Pit = Pit + AC(Yi,j)

This would mean Japanese exporters would bring fewer yen home per export sale

Overvalued currency exports will decrease, and imports are encouraged


Cutting to the chase……….

If you undervalue your currency, you are putting your economy on sale! (can you explain?)

If you overvalue your currency, you are making your economy’s products more expensive and will reduce exports and increase imports!

Suppose you would like to see an increase in employment in the U.S., a young senator rails for a strong $. Would you recommend he take some economics?


Lets take another look at the BigMac PPPs What countries have their currencies

undervalued? Are they known as major exporters?

Why did the Bush admin allow the $ to substantially weaken in value over the past two years of that admin?


Under valued exports encouraged

Imports discouraged

Overvalued

exports discouraged, imports encouraged


A minor complication! While exchange rates affect product trade they

can have an inverse effect on financial flows!

A strong currency (perhaps overvalued) means interest earned in that country can buy more in other countries……..so, money flows into countries with overvalued exchange rates!

This can offset the effects on product flows!@

(c) r.d. weaver 2004 in the real world, do currencies matter? adding some reality

Documents

real exchange rate ejit

real exchange rate ecompare

exchange rateppp

pjt ejit

foreign exchange markets

foreign exchange account

realityexchange rate

pjt pit