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Using Money to Buy Other Monies: Exchange Rates

15 一月, 2016 - 09:41

LEARNING OBJECTIVES

After you have read this section, you should be able to answer the following questions:

What is the difference between the nominal exchange rate and the real exchange rate?

How is the law of one price related to the nominal exchange rate?

As we all know, there are multiple currencies in the world. These are most often associated with a single country: the yen in Japan, the yuan in China, the peso in Mexico, and so on. Sometimes many countries will use the same money, with the leading example being the use of the euro by the member countries of the European Union (http://ec.europa.eu/economy_finance/euro/index_en.htm). Sometimes multiple currencies are in use in a single place: when you land at a major European airport, such as Frankfurt, Germany, or Amsterdam, the Netherlands, you will see that you can buy a cup of coffee at the airport using many different currencies. Likewise, the US dollar is freely accepted in some countries in addition to the local currency, British pounds formerly were freely accepted in Ireland, and so on.

If you happened to find your $100 right before going on a trip to another country, you might decide to use it to buy the money of that country. For example, if you were about to take a trip to Canada, you could take the bill into a bank or a foreign exchange merchant and exchange it for Canadian dollars. If you want to buy goods and services in Canada, you need Canadian dollars because they are the medium of exchange in that country.

When you make such an exchange, you buy the local currency using your home currency. If you travel from the United States to Europe, you buy euros using dollars. The price you pay is the dollar price of the euro: the amount in dollars you must pay to obtain 1 euro. This is completely analogous to using a dollar to buy a bottle of soda, when you pay the dollar price of soda. In practice, it is often unnecessary to carry out a physical exchange of notes and coins. In most countries, you can go to an automated teller machine (ATM) and withdraw local currency directly. Your bank deducts the equivalent sum in your home currency from your bank account. You are still carrying out an exchange, of course, but it is hidden from view, and you will see it only when you look at your next statement. The same is true if you make a purchase using a credit card.

Just as a US resident traveling to Europe wishes to buy euros with dollars, a visitor to the United States from, say, Holland will need to buy dollars with euros. The price she pays is the euro price of the dollar: the number of euros needed to obtain $1. The price of one currency in terms of another is called an exchange rate.

Toolkit:

If you want to review the definition of an exchange rate, you will find more details in the toolkit.

If we think of two currencies—euros and dollars, for example—then there are two exchange rates to keep in mind: the price of euros in dollars and the price of dollars in euros. (You might suspect, correctly, that these two prices are linked; we return to this shortly.) In a world of 3 currencies, each has a price in terms of the other two currencies, so there are 6 (= 3 × 2) different prices. And in a world of 100 currencies, then for each one, there are 99 prices for the other currencies. So there are 100 × 99 = 9,900 prices to quote! A Zambian traveling to Armenia wants to know about the kwacha price of drams, a Malaysian traveling to Oman is interested in the ringgit price of rials, and so on.