AP Syllabus focus: ‘When a currency depreciates, exports increase and imports decrease because domestic goods become relatively cheaper.’
A currency depreciation changes international relative prices. By making domestic products cheaper to foreign buyers and foreign products costlier to domestic buyers, it tends to raise exports and reduce imports.
Core mechanism: relative prices and trade flows
What a currency depreciation means
Currency depreciation: a decrease in the value of a currency in the foreign exchange market, so one unit of foreign currency exchanges for more units of the domestic currency.
Supply and demand in the foreign exchange market determine an equilibrium exchange rate (the “price” of one currency in terms of another). A depreciation can be represented as a movement to a new equilibrium where the domestic currency is weaker relative to the foreign currency (i.e., it takes more domestic currency per unit of foreign currency). This diagram reinforces that exchange rates are market prices, not just numbers quoted by banks. Source
Depreciation matters for trade because many export and import decisions depend on prices expressed in the buyer’s currency. When the domestic currency loses value, domestic output is “on sale” for foreigners, while foreign output becomes more expensive for domestic consumers and firms.
The “cheaper domestic goods” logic
Depreciation lowers the foreign-currency price of domestically produced goods and services (holding the domestic-currency price constant).
Depreciation raises the domestic-currency price of foreign-produced goods and services (holding the foreign-currency price constant).
Buyers substitute toward relatively cheaper options, changing the quantities of exports and imports.
How depreciation affects exports
Why exports tend to increase
Exports rise because foreign buyers can obtain more domestic output per unit of their own currency.
Foreign households can buy domestic consumer goods at a lower effective price.
Foreign firms can buy domestic intermediate goods and capital goods more cheaply.
Foreign tourists and students find domestic services less expensive.
What “exports increase” means in AP terms
For AP Macroeconomics, the key claim is about export quantity demanded:
If domestic goods become relatively cheaper, foreign demand increases, so the quantity of exports increases, other things equal.
Important ceteris paribus conditions
The expected increase in exports is strongest when these are stable:
The J-curve illustrates that after a currency depreciation, the trade balance can initially worsen before improving over time. In the short run, existing contracts and low short-run price responsiveness can keep import spending high (in domestic currency) even as the currency weakens. Over time, as quantities adjust and elasticities rise, exports tend to increase and imports tend to decrease, improving net exports. Source
Foreign income and overall foreign demand
Product quality and preferences for domestic vs. foreign brands
Trade regulations and shipping/transaction costs
How depreciation affects imports
Why imports tend to decrease
Imports fall because domestic buyers face higher prices for foreign goods in domestic currency.
Households reduce purchases of imported consumer goods as prices rise.
Firms reduce purchases of imported inputs when possible, switching to domestic substitutes.
Domestic travel abroad becomes more expensive, reducing imported tourism services.
What “imports decrease” means in AP terms
Again, the emphasis is on quantity imported:
As foreign goods become relatively more expensive, the quantity of imports demanded decreases, other things equal.
When the import response is limited
Even with depreciation, imports may not fall much in quantity if:
There are few domestic substitutes (e.g., specialized components)
Imports are necessities with less responsive demand
Production requires imported inputs that cannot be easily replaced
FAQ
Export revenue depends on both price and quantity, and pricing may adjust.
If foreign-currency prices fall a lot, total foreign-currency revenue can be ambiguous even with higher sales volume.
Pass-through is how much a change in the exchange rate changes the domestic price of imports.
If foreign firms cut their mark-ups, import prices may rise less than expected, weakening the fall in import quantity.
If exporters rely heavily on imported components, depreciation raises their input costs in domestic currency.
That cost increase can force higher export prices, reducing the competitiveness gain.
Often yes: foreigners find domestic services cheaper, while domestic residents find foreign services dearer.
However, capacity constraints (hotels, universities) can limit how much service exports expand.
Contracts, delivery lags, and adjustment costs can delay changes in quantities.
Firms and consumers may need time to find suppliers, redesign products, or switch spending patterns.
Practice Questions
(2 marks) Define currency depreciation and state its expected effect on exports and imports.
1 mark: Correct definition (value of currency falls; more domestic currency per unit foreign currency).
1 mark: States exports rise and imports fall (in quantity), ceteris paribus.
(6 marks) Explain how a depreciation of a country’s currency affects (i) export demand and (ii) import demand. Your answer must use relative prices and the incentives faced by buyers.
Up to 3 marks exports: depreciation makes domestic goods cheaper in foreign currency; foreign buyers’ purchasing power rises; quantity demanded of exports increases (any three well-linked points).
Up to 3 marks imports: foreign goods more expensive in domestic currency; domestic buyers substitute away; quantity demanded of imports decreases (any three well-linked points).
