Lesson preview · Trade And Exchange Rates
Trade & Exchange Rates
~12 min · Free to read
A euro that cost 1.10 dollars last year now costs 1.30 dollars. Nothing else changed, yet a European holiday just got pricier for Americans, and an American gadget just got cheaper for Europeans. That single number — the price of one currency in another — quietly reshapes who buys what across borders. This lesson explains what an exchange rate is, what moves it, and the surprising path a country’s trade balance takes when its currency falls.
Key Term
Exchange rate, appreciate, depreciate
An exchange rate is the price of one currency in terms of another. If a euro costs 1.10 dollars, that is the euro-dollar exchange rate.
When a currency gets stronger — worth more of the other currency — it appreciates. A euro rising from 1.10 dollars to 1.30 dollars has appreciated: each euro now buys more dollars.
When a currency gets weaker — worth less of the other — it depreciates. A euro falling from 1.10 dollars to 0.90 dollars has depreciated: each euro now buys fewer dollars.
Keep the direction straight: a stronger home currency makes foreign goods cheaper for you, while a weaker home currency makes your exports cheaper for foreigners.
The number above is the nominal exchange rate — the plain market price of the currency. But that price alone does not tell you how good a deal foreign goods really are, because prices differ from country to country. For that you need the real exchange rate.
Key Term
Nominal vs real exchange rate
The nominal exchange rate is just the market price of the currency — how many dollars a euro costs today.
The real exchange rate adjusts that price for how expensive goods are in each country. It tells you how many foreign goods one home good trades for. A cheap currency does not help your exporters if your own prices have shot up to match — the real rate strips that out so you can compare goods to goods, not just currency to currency.
Example: your currency depreciates 10 percent (cheaper money), but your prices also rose 10 percent while the other country’s held steady. In real terms nothing changed — your goods are no cheaper abroad than before.
Real exchange rate as the nominal rate adjusted for relative price levels.
Key Term
What moves exchange rates
Four forces push a currency up or down:
- Relative interest rates. Higher rates at home attract foreign money chasing a better return, so demand for the home currency rises and it appreciates.
- Relative inflation. A country with higher inflation sees its money lose buying power faster, so its currency tends to weaken over time.
- Trade flows. When foreigners want more of a country’s exports, they must buy its currency to pay for them, which pushes the currency up.
- Expectations and speculation. If traders expect a currency to rise, they buy it now — and that buying can make the rise happen.
That is all a floating exchange rate is — a price set by the market rather than pegged by a government — so whenever a shock shifts the demand for a currency or its supply, the rate moves until the two agree again.
Now the payoff. Suppose a currency depreciates — it gets cheaper. Common sense says cheaper exports should improve the trade balance straight away. They do not. In the months right after, the trade balance usually gets WORSE before it gets better. The reason is timing.
Key Term
The J-curve
The trade balance is the value of what a country sells abroad (exports) minus the value of what it buys from abroad (imports).
Right after a depreciation, the volumes — how many goods are actually shipped each way — are stuck. Contracts are already signed and orders already placed, so the same imports keep arriving. But each import now costs more in home-currency terms, because the home currency is weaker. Same quantity, higher bill: the trade balance falls.
Over time the volumes adjust. Cheaper exports win more foreign buyers, and pricier imports get bought less. Exports rise, imports fall, and the trade balance recovers — ending up higher than before the depreciation.
Plot the balance over time and it dips, then climbs: the path traces the letter J. That is the J-curve.
Trap · Common Misconception
"A cheaper currency fixes the trade deficit right away"
It feels obvious that a weaker currency, by making exports cheaper, should shrink a trade deficit immediately. It does the opposite at first. In the short run trade volumes are locked in by existing contracts, so a depreciation mainly just raises the home-currency cost of the same imports — the balance worsens. Only after months, once buyers respond and volumes shift, does the balance recover and improve. The relief is real, but it is delayed.
Tip
So what?
A weaker currency makes the trade balance worse before it makes it better, because trade volumes take time to respond — and that delay is exactly what traces the J-curve.
Worked Example
A country’s currency depreciates by 15 percent. Its finance minister expects the trade deficit to shrink within the month, because exports are now cheaper for foreigners. Three months later the deficit has actually grown. Explain what happened and what the minister should expect over the next two years.
Check yourself · no marks
Two countries have the same nominal exchange rate against the dollar. Country A’s prices have been rising fast; Country B’s have been flat. Whose exports are the better deal for American buyers, and why?
Commit to one first. Guessing and being wrong beats reading the answer cold.
One more force shapes trade besides the exchange rate: governments can tax it directly. Picture a small country that can buy any amount of a good at the fixed world price — its purchases are too small to move that price. At the world price, domestic firms supply part of what consumers buy, and imports fill the gap between the two. A tariff — a tax on each imported unit — pushes the home price above the world price, and the widget below shows exactly who wins, who loses, and what simply disappears.
Consumers pay for all four regions, but only two of them land anywhere — the producer gain and the government’s revenue. The red triangles just vanish.
Practice · 1 / 4
A euro rises from 1.10 dollars to 1.30 dollars. What has happened to the euro?
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