Exchange rates

Introduction to Exchange Rates

Welcome to one of the most exciting parts of Economics! Have you ever wondered why the price of a holiday abroad changes from one month to the next, or why an iPhone costs more in some countries than others? It often comes down to exchange rates. In this chapter, we will explore how currencies are traded like any other good and how their "price" affects the entire economy. Don't worry if this seems tricky at first—once you see it as a simple case of supply and demand, it all clicks into place!

6.4.1 What is an Exchange Rate?

An exchange rate is simply the price of one currency shown in terms of another currency. Think of it as a conversion ratio. For example, if the exchange rate is \( £1 = \$1.25 \), it means you need 1.25 US Dollars to "buy" 1 British Pound.

Analogy: Imagine you are at a fruit stall. If 1 Apple = 2 Oranges, the "exchange rate" for apples is 2 oranges. In the global market, instead of fruit, we are just swapping different types of paper money!

Key Takeaway: An exchange rate is the external value of a currency.

6.4.2 How is a Floating Exchange Rate Determined?

In a floating exchange rate system, the value of the currency is decided entirely by the market forces of demand and supply. The government or central bank does not try to fix the rate at a specific level.

• Demand for a currency: This comes from people outside the country who want to buy that country's goods (exports), travel there as tourists, or invest in that country's banks and businesses.
• Supply of a currency: This comes from people within the country who want to buy foreign goods (imports), travel abroad, or invest in other countries. To do these things, they must "sell" their own currency to get the foreign one.

The equilibrium exchange rate is found where the demand curve for the currency crosses the supply curve. If demand goes up, the price goes up. If supply goes up, the price goes down.

Quick Review: Who demands the Pound (£)? Foreigners wanting to buy British stuff. Who supplies the Pound (£)? British people wanting to buy foreign stuff.

6.4.3 Appreciation vs. Depreciation

In a floating system, we use specific words to describe when the value of a currency changes:

1. Appreciation: This is when the value of a currency increases. It becomes "stronger."
Example: If the rate moves from \( £1 = \$1.25 \) to \( £1 = \$1.30 \), the Pound has appreciated.

2. Depreciation: This is when the value of a currency decreases. It becomes "weaker."
Example: If the rate moves from \( £1 = \$1.25 \) to \( £1 = \$1.20 \), the Pound has depreciated.

Memory Aid:
• Appreciation = Adds value (Up).
• Depreciation = Down in value.

Did you know? In a pair of currencies, if one appreciates, the other must depreciate. If the Pound gets stronger against the Dollar, the Dollar is automatically getting weaker against the Pound!

6.4.4 Why do Floating Exchange Rates Change?

Since the rate is decided by demand and supply, anything that shifts those curves will change the exchange rate. Here are the main causes:

1. Changes in Interest Rates: If a country raises its interest rates, foreign investors will want to put their money in that country's banks to earn more profit. To do this, they demand more of that currency. This is often called "Hot Money" flows. Higher interest rates usually lead to appreciation.

2. Inflation Rates: If a country has high inflation, its goods become more expensive and less competitive. People will buy fewer exports (lower demand for currency) and buy more imports (higher supply of currency). High inflation usually leads to depreciation.

3. Demand for Exports and Imports: If the world suddenly wants to buy a country's products (e.g., a new technology), demand for the currency rises, causing appreciation.

4. Investment (FDI): If foreign companies build factories in a country (Foreign Direct Investment), they need to buy the local currency to pay for construction and workers. This increases demand and causes appreciation.

5. Speculation: If speculators (people who trade money for profit) think a currency will rise in the future, they will buy it now. This increase in demand causes the value to actually rise!

Key Takeaway: Think "Demand and Supply." If people want the currency more, it appreciates. If they want it less (or sell it more), it depreciates.

6.4.5 Impact of Exchange Rate Changes (AD/AS Analysis)

This is a favorite topic for exam questions! How does a change in the exchange rate affect the whole economy? We use two famous mnemonics to remember this.

If the Currency Appreciates (Gets Stronger)

Use the mnemonic: SPICED (Strong Pound Imports Cheap Exports Dear/Expensive).

• Impact on Aggregate Demand (AD): Exports are more expensive for foreigners to buy, so export volume falls. Imports are cheaper for locals, so import volume rises. Since \( Net Exports (X - M) \) is a component of AD, AD will shift to the left.
• Real Output and Employment: As AD falls, economic growth may slow down, and unemployment might rise in export-driven industries.
• Price Level (Inflation): A stronger currency helps lower inflation. Why? Because imported raw materials are cheaper, and the fall in AD reduces "demand-pull" inflation.

If the Currency Depreciates (Gets Weaker)

Use the mnemonic: WPIIDEC (Weak Pound Imports Dear Exports Cheap).

• Impact on Aggregate Demand (AD): Exports are now cheaper for foreigners, so they buy more. Imports are more expensive for locals, so they buy fewer. This causes \( (X - M) \) to rise, and AD shifts to the right.
• Real Output and Employment: Higher AD leads to higher real output (economic growth) and can create more jobs in the export sector.
• Price Level (Inflation): A weaker currency can cause inflation. Imported raw materials (like oil) become more expensive ("cost-push" inflation), and the rise in AD can cause "demand-pull" inflation.

Common Mistake to Avoid: Don't just say "exports increase." Be specific! Say "the value of net exports increases, which shifts the AD curve to the right."

Quick Review Box

• Appreciation: AD falls \(\rightarrow\) Growth falls \(\rightarrow\) Inflation falls.
• Depreciation: AD rises \(\rightarrow\) Growth rises \(\rightarrow\) Inflation rises.

Final Encouragement: Exchange rates can feel like a lot of moving parts, but just remember: it's all about how expensive or cheap a country's "stuff" becomes to the rest of the world. Master SPICED and WPIIDEC, and you'll be ready for any question!