Currencies Are Just Prices for Money
When you stand at a Tokyo bus stop and try to convince a vending machine that your $1 bill should buy you a can of green tea, the machine has a problem: it doesn't speak dollar. The vending machine wants yen. Somewhere, somehow, before you can buy that drink, your $1 has to be converted into ¥150 or thereabouts. The number that determines how many yen one dollar buys is the exchange rate — and even though it feels exotic, it's nothing more than a price. A price for money itself, denominated in some other money.
For five and a half units now, we've treated all transactions as if they happened in a single currency. Section 6.1 cracked that assumption open with the Balance of Payments. Now in 6.2, we'll dig into the specific number that governs every international transaction: the exchange rate. By the time you finish this section, three things should be automatic:
- You can read any exchange rate quote and tell which currency is "strong" and which is "weak," and what those words mean precisely.
- You can predict how a currency's appreciation or depreciation will affect exports, imports, net exports, and aggregate demand — every single time, without hesitation.
- You know the three exchange rate systems (floating, fixed, managed float) and what governments do under each.
The mechanics here are arithmetic-light, but the vocabulary is precise. Many AP students lose points not because they don't understand exchange rates — they understand them fine — but because they confuse "appreciation" with "appreciation in price level" (inflation), or mix up which way to flip a ratio. Let's nail the vocabulary down first.
📝 The exam pattern you're being prepared for: Almost every AP Macro exam tests exchange rate vocabulary with a small calculation or a "which way does the currency move?" question. There will also be a chain question asking how exchange rate changes feed through into net exports and aggregate demand. By the end of this section, both of those patterns will be reflex.
What an Exchange Rate Actually Is
Forget for a moment everything you've heard on the news about exchange rates being "strong" or "weak" or "tanking" or "soaring." Strip the drama away. An exchange rate is just a number that tells you: how many units of currency B do you get for one unit of currency A? That's it. It's a ratio.
Exchange Rate: The price of one currency expressed in terms of another currency. If $1 trades for ¥150 on the foreign exchange market, then the exchange rate of the dollar in terms of the yen is 150 — meaning one dollar buys 150 yen. Equivalently, the exchange rate of the yen in terms of the dollar is 1/150 ≈ 0.0067 — one yen buys about two-thirds of a U.S. penny.
Every Exchange Rate Has Two Sides
This is the part that trips up most students. There's no single "the dollar-yen exchange rate." There are two of them — one for each direction — and they're reciprocals. If you tell me $1 = ¥150, you've told me two things at once:
$1 = ¥150 ⟺ ¥1 = $1/150 ≈ $0.0067
Flip the ratio, get the inverse exchange rate. Both are correct; they're the same fact stated in two different units.
This sounds obvious, but it matters because AP questions deliberately phrase exchange rates in either direction, and you have to know which one you're looking at. "The exchange rate is 1.2 euros per dollar" and "the dollar is worth 0.83 euros" describe identical situations — just with different units on the y-axis. The exam tests whether you can flip between them fluently.
Reading the Units Carefully
The way to keep yourself out of trouble is to always pay attention to the units. When someone says "the exchange rate is 150," your immediate next question should be: "150 of what per what?" Without units, the number is meaningless. With units, it becomes precise.
| Way of saying it | What it means | Same fact, flipped |
|---|---|---|
| "The exchange rate is ¥150 per dollar" | $1 buys ¥150 | $0.0067 per ¥1 |
| "The dollar is worth ¥150" | Same as above. $1 = ¥150 | ¥1 is worth $0.0067 |
| "The exchange rate is 1.2 euros per dollar" | $1 buys €1.20 | €1 buys $0.833 (= 1/1.2) |
| "€1 = $1.20" | €1 buys $1.20 | $1 buys €0.833 (= 1/1.2) |
🎯 Survival rule for AP exchange rate problems: Before doing anything, circle the units. "Yen per dollar" means the dollar is in the denominator and going up means more yen per dollar — i.e., the dollar is appreciating. "Dollars per yen" means the yen is in the denominator and going up means more dollars per yen — i.e., the yen is appreciating. Same direction of arrow, opposite economic meaning. Units matter.
Appreciation vs. Depreciation
Now we get to the two pieces of vocabulary that will drive every AP Macro question on this topic. A currency can either get "stronger" (appreciation) or "weaker" (depreciation). These are precise, technical terms — not opinions, not metaphors.
Appreciation
The currency can now buy more of a foreign currency than before. One unit of it has greater "purchasing power" over foreign goods.
Example: Last month $1 bought ¥100. This month $1 buys ¥150. The dollar has appreciated against the yen.
Implication for trade:
- U.S. exports become more expensive for foreign buyers (foreigners need more of their currency to get the same dollar amount).
- Imports become cheaper for Americans (each dollar buys more foreign currency, so foreign goods cost fewer dollars).
- Net exports (X − M) decrease.
Depreciation
The currency can now buy less of a foreign currency than before. One unit of it has reduced "purchasing power" over foreign goods.
Example: Last month $1 bought ¥150. This month $1 buys only ¥100. The dollar has depreciated against the yen.
Implication for trade:
- U.S. exports become cheaper for foreign buyers (foreigners need less of their currency to get the same dollar amount).
- Imports become more expensive for Americans (each dollar buys less foreign currency, so foreign goods cost more dollars).
- Net exports (X − M) increase.
A Visual: Appreciation vs. Depreciation in One Picture
Why the Trade Effects Go the Way They Do
The trade implications of appreciation and depreciation aren't arbitrary rules to memorize. They follow from one simple fact: when a currency gets stronger, anyone who has to convert into that currency to buy your country's goods faces a higher effective price. Let's walk through it with concrete numbers, because the AP exam loves to test this with prices and amounts.
An American iPhone is priced at $1,000 in U.S. dollars
When Apple ships an iPhone to Japan, it still wants to receive $1,000 per unit. The Japanese consumer is the one who has to convert yen into dollars.
If the dollar appreciates from ¥100 to ¥150 per dollar...
A Japanese consumer who used to need ¥100,000 to buy that $1,000 iPhone (at ¥100/$1) now needs ¥150,000 (at ¥150/$1). The iPhone became 50% more expensive in yen, with no change in its dollar price.
Japanese consumers buy fewer iPhones
Higher yen prices mean less Japanese demand for U.S. exports. U.S. exports to Japan fall.
Meanwhile, a Toyota priced at ¥3,000,000 in Japan...
An American buyer used to need $30,000 (at ¥100/$1) to convert into ¥3,000,000. Now she only needs $20,000 (at ¥150/$1). The Toyota became 33% cheaper in dollars, with no change in its yen price.
Americans buy more Toyotas
Cheaper dollar prices on foreign goods mean more U.S. demand for imports. U.S. imports from Japan rise.
Net exports fall → AD shifts left
Exports down, imports up, so net exports (X − M) decrease. Since net exports are a component of aggregate demand, AD shifts left. Output and employment soften; the price level eases. This is the entire reason exchange rates matter for macroeconomic policy.
The depreciation story is the mirror image: cheaper exports, more expensive imports, net exports rise, AD shifts right. Same logic, reversed direction.
"SPICE" — Strong currency = Imports Cheap, Exports Expensive
Strong currency — purchasing power is up.
Purchasing more foreign currency per unit.
Imports are Cheap (one unit of your currency now buys more foreign currency, so foreign goods cost less in your units).
Exports are Expensive (foreigners need more of their currency to get one unit of yours, so your goods cost more in their units).
Result: X falls, M rises, net exports decrease. The exact opposite holds for a weak currency.
The Mirror Rule: One Currency's Gain Is Another's Loss
An exchange rate is a ratio between two currencies. If one of them gets stronger, the other one has to get weaker by exactly the same amount — there's no third option. The dollar can't appreciate against the yen without the yen depreciating against the dollar. They're two ways of saying the same thing.
Dollar appreciates against yen ⟺ Yen depreciates against dollar
Every exchange-rate movement is two events: appreciation of one currency and depreciation of the other.
This is the "mirror rule," and AP exam questions love to test whether you can switch perspectives smoothly. If the question describes a scenario from the U.S. perspective ("the dollar weakens against the euro"), and the answer choices describe the same event from the European perspective ("the euro strengthens against the dollar"), they're describing the same exchange rate movement. You need to be able to translate between perspectives without thinking.
Practicing the Mirror Rule
Translate Each Statement to Its Mirror
For each statement on the left, write the equivalent statement from the other currency's perspective:
Get fluent at this. AP exams will phrase the same movement from either side and trust that you can flip the perspective.
⚠️ The "two currencies, one question" trap: AP exam questions may show you a FOREX graph for the dollar, then ask what happens to the yen. Don't panic and don't try to draw a separate yen graph. Just remember the mirror rule: whatever happened to the dollar happened in the opposite direction to the yen. If the dollar appreciated 20%, the yen depreciated 20% (well, approximately — the math isn't exactly symmetric for large moves, but for AP purposes treat them as exactly opposite).
Exchange Rate Systems
Not all exchange rates are determined the same way. There are three broad systems a country can choose, and the choice has huge implications for how monetary policy works, how much foreign-currency reserves the country needs, and whether the central bank ever has to "defend" its currency.
| System | How the exchange rate is determined | Real-world examples |
|---|---|---|
| Floating (Flexible) | The exchange rate is set entirely by supply and demand in the foreign exchange market. The government and central bank don't intervene. The currency can appreciate or depreciate freely as economic conditions change. | U.S. dollar, euro, Japanese yen, British pound, Australian dollar — most of the world's major currencies today. |
| Fixed (Pegged) | The government commits the currency to a specific exchange rate against another currency (or a basket of currencies). The central bank stands ready to buy or sell its own currency in the FOREX market to keep the rate at the chosen peg. | Hong Kong dollar (pegged to USD), Saudi riyal (pegged to USD), historically the Chinese yuan was tightly pegged to the dollar; many small economies still peg. |
| Managed Float | Mostly floating, but the central bank occasionally intervenes to smooth out extreme fluctuations or push back against speculative attacks. There's no announced peg, but the government has views on what the rate "should" be. | Modern China (managed float against a basket of currencies), India, Brazil, Singapore. In practice the most common system worldwide. |
Vocabulary Under Each System
The AP exam distinguishes between two pairs of words depending on which system is in use. Mix them up at your peril.
Appreciation & Depreciation
Under a floating exchange rate, the market sets the rate. When the currency gains value, we say it has appreciated. When it loses value, it has depreciated. The currency moved on its own, driven by market forces.
Cause: Market participants' choices — investors, exporters, importers, tourists, speculators.
Revaluation & Devaluation
Under a fixed exchange rate, the government picks the rate. If the government decides to set a stronger peg (currency now buys more foreign currency), it's called a revaluation. If the government sets a weaker peg, it's called a devaluation.
Cause: A deliberate policy decision by the government or central bank.
🎯 AP language rule: Currencies "appreciate" and "depreciate" only under floating systems. Under fixed systems, governments "revalue" and "devalue." If an AP question describes a country with a fixed exchange rate and asks what happens when policymakers strengthen the currency, the correct word is revaluation, not appreciation. The distinction is tested.
How Governments Defend a Fixed Exchange Rate
Pegging a currency isn't a free policy. To maintain a fixed exchange rate, the central bank has to be willing to intervene in the FOREX market whenever the market price drifts away from the pegged price. The mechanics:
If market pressure would push the currency weaker than the peg...
(Imagine speculators are dumping the currency, threatening to drive its market value below the pegged rate.) The central bank must buy its own currency, using its foreign-currency reserves. This shifts demand for the currency up, supporting the peg.
If market pressure would push the currency stronger than the peg...
The central bank must sell its own currency (creating new units of it) and buy foreign currency. This adds to the supply of its currency, pushing market price back down to the peg.
The catch: reserves can run out
To defend a weak peg, the central bank needs foreign currency reserves. If reserves run out, the peg collapses — a "currency crisis." This is why countries like Argentina, Thailand (1997), and Mexico (1994) all eventually had to abandon their pegs. To defend a strong peg, the central bank can in principle create unlimited domestic currency — so this side is sustainable indefinitely (China's situation for many years).
⚠️ Note on AP exam focus: The exam mostly tests the floating system, since that's how the U.S. and most modern major economies operate. Fixed-system mechanics show up occasionally but rarely in deep technical questions. Make sure you know vocabulary for both systems, but you can spend most of your study time on floating-system supply-and-demand analysis (which is the focus of Section 6.3).
Working with Exchange Rate Calculations
Exchange rate problems on the AP exam are almost always one of three flavors: (1) convert a price from one currency to another, (2) compute the reciprocal of a given exchange rate, or (3) compute a cross rate between two currencies using a third currency as a bridge. The math is simple multiplication and division, but the AP exam expects you to do it cleanly under pressure.
Type 1: Converting a Price Between Currencies
The Restaurant Meal Problem
Scenario: The exchange rate is 1.2 euros per U.S. dollar (i.e., $1 = €1.20). A restaurant meal costs €30 in Paris. What is the dollar cost to a U.S. tourist?
Step 1 — Identify the units: The exchange rate is given as €/$, but you want a dollar price. So you'll need to flip the rate, or just divide.
Step 2 — Apply the conversion: If $1 buys €1.20, then €1 = $1/1.20 = $0.833. So €30 × $0.833/€ = $25.
Equivalent approach (cleaner for this direction): Convert directly by dividing the foreign price by the exchange rate when the exchange rate is given as "foreign per dollar."
Dollar price = €30 ÷ (€1.20 per $1) = $25
Sanity check: If the dollar is "strong" relative to the euro ($1 buys more than €1), then a euro meal should cost fewer dollars than its euro price. €30 should cost less than $30 — and indeed $25 is less than $30. ✓
Type 2: Computing the Reciprocal
Yen-to-Dollar to Dollar-to-Yen
Scenario: The exchange rate is reported as ¥150 per dollar. What is the exchange rate in dollars per yen?
Step 1 — Recognize this is a reciprocal: If $1 = ¥150, then ¥1 = $1/150.
Step 2 — Compute: $1/150 = $0.00667 (approximately two-thirds of a U.S. penny per yen).
Common student error: Some students see "150" and try to use 150 as the exchange rate in both directions. Always flip — the two directions of an exchange rate are reciprocals, not the same number.
Type 3: Cross Rates (Two Currencies via a Third)
Yen, Euro, Dollar — Triangulation
Scenario: A table shows two exchange rates: ¥150 per dollar, and ¥165 per euro. Which of the following must be true?
(A) One euro is worth $0.50.
(B) One euro is worth $1.10.
(C) Goods are cheaper in the Eurozone than in the U.S.
(D) The yen has depreciated.
Step 1 — Find the cross rate between euros and dollars: If ¥150 = $1 and ¥165 = €1, then €1 = ¥165 = (165/150) × $1 = $1.10.
Step 2 — Sanity check: €1 buys more yen than $1 does (165 vs. 150), so the euro should be worth more than a dollar. $1.10 is more than $1.00. ✓
Type 4: Identifying the Direction of Movement
"From 12 to 13 Yen per Krona": Who Moved?
Scenario: The price of the Swedish krona changes from 12 yen per krona to 13 yen per krona. What happened to the yen, and what happened to the cost of Swedish goods to Japanese residents?
Step 1 — Read the units: The rate is "yen per krona." This is the price of a krona, in yen. When the price of a krona rises from ¥12 to ¥13, the krona has gotten more expensive (in yen). That means the yen has depreciated against the krona.
Step 2 — What about Swedish goods? If a Swedish good costs 10 krona, it used to cost a Japanese consumer 10 × ¥12 = ¥120. Now it costs 10 × ¥13 = ¥130. Swedish goods became more expensive for Japanese residents.
Connecting the dots: Yen depreciation means each yen buys less foreign currency, so foreign goods (priced in foreign currency) cost more in yen. This is the SPICE mnemonic at work in reverse.
🎯 Universal calculation strategy: Always start by writing down the exchange rate with explicit units (e.g., "150 yen / dollar," not just "150"). Then ask: "What units does my answer need to be in?" The math will take care of itself if the units cancel correctly. If yen/dollar × dollars = yen, you're converting in the right direction. If yen/dollar × yen, that's nonsense — flip the rate.
A Preview: What Causes Exchange Rates to Change?
By now you know what an exchange rate is, what its direction means for trade, and how the math works. The natural next question is: what makes exchange rates move in the first place? That's the subject of Section 6.3 — the foreign exchange market, where supply and demand for currencies are graphed and analyzed in detail. But it's worth previewing the big drivers now, because they connect everything you've already learned in Units 4 and 5 to what's coming.
The Four Big Drivers of Exchange Rates
Under a floating system, the exchange rate of a country's currency tends to move because of changes in one or more of these factors. We'll graph them properly in 6.3, but the intuition is straightforward:
| Factor | Effect on the country's currency | Why |
|---|---|---|
| Higher domestic interest rates | Appreciates | Higher returns attract foreign investors → they demand more of the currency to buy domestic bonds. |
| Higher domestic income/GDP | Depreciates | Richer consumers buy more imports → more domestic currency supplied on the FOREX market to obtain foreign currency. |
| Higher domestic inflation (relative to trading partners) | Depreciates | Domestic goods become relatively expensive → foreigners buy fewer (less demand for currency); domestic residents buy more imports (more supply of currency). |
| Higher foreign demand for domestic exports | Appreciates | Foreigners need more of the currency to buy more exports → demand for currency rises. |
The single most important chain to internalize — because the AP exam loves it — is the interest rate → exchange rate → net exports chain. We covered most of the steps in earlier units. Here's the full sequence:
Fed raises interest rates (Unit 4 monetary policy)
Tighter monetary policy pushes the nominal interest rate up.
Higher U.S. rates attract foreign investors
U.S. bonds and assets now offer higher returns than before. Foreign investors want in.
Demand for dollars rises in the FOREX market
To buy U.S. assets, foreign investors must first get dollars. Demand for the dollar shifts right.
The dollar appreciates
More demand for the dollar at the same supply means a higher price (more yen per dollar, more euros per dollar, etc.).
U.S. exports become more expensive; imports become cheaper
Foreigners need more of their currency to buy U.S. exports, so X falls. Americans need fewer dollars to buy imports, so M rises.
Net exports (Xn) decrease → AD shifts left
The exchange-rate channel reinforces the contractionary effect of the original monetary policy. Tighter money, weaker exports, less AD — a double hit.
This is the master chain that runs from monetary policy through the exchange rate to aggregate demand. We'll build the FOREX graphs to support each step in Section 6.3, and we'll lay out the full implications for fiscal vs. monetary policy in Section 6.4. For now, just appreciate (no pun intended) that exchange rates aren't isolated — they're a transmission belt connecting interest rates to trade flows.
🎯 The Unit 6 master picture: Section 6.1 is the accounting framework (BOP, CA, FA). Section 6.2 (this one) is the vocabulary and concept of exchange rates. Section 6.3 is the supply/demand model of the FOREX market that explains why exchange rates move. Section 6.4 connects everything to fiscal and monetary policy from earlier units. After all four sections, you'll be able to trace any policy change from its starting point through interest rates, exchange rates, net exports, and back into aggregate demand — the full open-economy story.
Common Misconceptions
Exchange rates are conceptually simple but linguistically slippery. Each of the misconceptions below has appeared as a wrong-answer choice on real AP exams.
- "A strong currency is always good for the economy." Not necessarily. A strong currency makes imports cheaper (good for consumers) but exports more expensive (bad for domestic exporters and the workers they employ). Whether a strong currency is "good" depends entirely on which side of the trade equation you're on.
- "Appreciation means inflation." No. Currency appreciation is the currency getting more valuable relative to other currencies. Inflation is prices rising in your own currency. They're related (high inflation tends to cause depreciation), but they're not the same thing. A currency can appreciate even when inflation is low — that's actually the typical pattern.
- "If $1 buys 150 yen, then ¥1 buys 1/150 of a dollar." OK so far. "Therefore, the dollar is worth 150 times more than the yen." The first statement is right, the conclusion misuses "worth." The dollar isn't 150 times "more valuable" in any deep sense — it's just denominated in larger units. The U.S. and Japan have similar per-capita GDPs; the yen's number is bigger only because Japan never re-denominated after WWII. The exchange rate of two currencies reflects relative scarcity in the FOREX market, not relative wealth of the countries.
- "A country can have its currency appreciate against one foreign currency and depreciate against another at the same time." Yes, this can absolutely happen, and it does all the time. A currency's overall strength is the weighted average across all its trading partners. The U.S. dollar might appreciate against the yen while depreciating against the euro in the same quarter.
- "In a fixed exchange rate system, the currency can still appreciate or depreciate." Misuse of vocabulary. Under a fixed system, the central bank holds the currency at the chosen rate by intervening. The currency does not "appreciate" or "depreciate" on its own — it is "revalued" or "devalued" by policy action.
- "Depreciation hurts the country, appreciation helps it." Both are mixed bags. Depreciation helps exporters and the trade balance but hurts consumers (imports cost more) and anyone with debt in foreign currency. Appreciation helps consumers and importers but hurts exporters. Neither is unambiguously "good" or "bad."
- "The exchange rate is the same as the interest rate." Different concepts entirely. The interest rate is the return on holding a financial asset (a bond, a savings account). The exchange rate is the price at which two currencies trade. They're linked — higher interest rates tend to appreciate a currency — but they're not the same number.
- "A trade deficit causes a currency to depreciate." Not necessarily, and often not. The U.S. has run a persistent trade deficit for decades while the dollar has remained strong, because foreign demand for U.S. assets (Treasury bonds especially) creates demand for the dollar that outweighs the supply created by the trade deficit. The exchange rate reflects all demand and supply for the currency, not just the trade balance.
- "To make a currency stronger, just print more of it." Backwards. Printing more of a currency increases its supply, which lowers its price — i.e., depreciates it. Restricting the money supply (or running higher interest rates) tends to strengthen a currency. This is one reason the Fed's policy choices have international consequences.
- "In the long run, exchange rates always return to their starting point." No. There's no automatic mean-reversion mechanism for nominal exchange rates. They can drift in one direction for years — the dollar can stay strong (or weak) against the yen for an entire decade. Purchasing power parity is a long-run tendency in some models, but it's loose enough that the AP exam doesn't expect you to invoke it.
⚡ 6.2 Quiz: 5 Questions
Click an answer to lock it in. Every option gets a full breakdown — what's right, what's wrong, and the AP-favorite trap each distractor is designed to catch.
1. The exchange rate is 1.2 euros per United States dollar. If a restaurant meal costs €30 in Paris, France, what is its dollar cost to a U.S. tourist?
✓ Correct answer: (C)
The exchange rate is €1.20 per $1, which means $1 buys €1.20. To convert €30 into dollars, divide by the exchange rate: €30 ÷ (€1.20/$1) = $25. Equivalently, since each euro is worth $1/1.20 = $0.833, multiply: €30 × $0.833 = $25. A quick sanity check: the dollar is stronger than the euro here ($1 buys more than €1), so a euro-priced meal should cost fewer dollars than its number in euros. $25 is less than $30 — direction is correct.
Why the other options miss the mark
- (A) $2.50 misplaces a decimal point. It would be the answer if the exchange rate were €12 per dollar (it's €1.20).
- (B) $3.60 has no clean derivation from these numbers — likely a distractor designed to look mathematical.
- (D) $30 would be the answer only if $1 = €1 (a 1-to-1 rate). The actual rate isn't 1-to-1.
- (E) $36 is the classic multiplication error: €30 × 1.2 gives the wrong direction.
🔗 Review: Re-read Worked Example 1 in "Working with Exchange Rate Calculations." Key rule: always check that your answer makes directional sense based on which currency is stronger.
2. A decrease in the value of a nation's currency in a flexible exchange rate system is called
✓ Correct answer: (B)
This is a pure vocabulary check. Under a flexible (i.e., floating) exchange rate system, when a currency loses value against other currencies, the precise term is depreciation. The market drove the value down through supply and demand — no government action was needed. The opposite (currency gains value under a floating system) is called appreciation.
Why the other options miss the mark
- (A) Deflation is a decrease in the price level within a country, measured in the country's own currency. It's different from a currency losing value internationally.
- (C) A trade deficit is a Balance of Payments concept (imports exceeding exports), not a description of an exchange rate movement.
- (D) Devaluation applies only under fixed exchange rate systems. The question specifies a flexible system.
- (E) Capital flight is rapid outflow of financial capital from a country (often during a crisis). It can cause depreciation, but it's not the same thing.
🔗 Review: Re-read "Vocabulary Under Each System." The pairing: floating → appreciation/depreciation; fixed → revaluation/devaluation. Mixing the pairs is a common AP-exam trap.
3. The price of the Swedish krona changes from 12 Japanese yen per krona to 13 Japanese yen per krona. Which of the following describes the change in the yen and the change in the cost of Swedish goods to residents of Japan?
✓ Correct answer: (D)
Carefully read the units: the exchange rate is given as "yen per krona," which means we're seeing the price of a krona, expressed in yen. When this number rises from 12 to 13, the krona has gotten more expensive in yen terms — meaning the yen now buys fewer kronor. The yen has depreciated against the krona. As a result, any Swedish good priced in kronor now costs more yen for a Japanese consumer. For example, a Swedish item priced at 10 krona used to cost 10 × ¥12 = ¥120; now it costs 10 × ¥13 = ¥130. Swedish goods cost more to Japanese residents.
Why the other options miss the mark
- (A) Yen depreciation is correct, but Swedish goods would cost more, not less, to Japanese consumers.
- (B) The cost of Swedish goods changes when the exchange rate changes. It cannot be unchanged.
- (C) The yen depreciated, not appreciated. The number is yen per krona — a rising number means the krona, not the yen, is appreciating.
- (E) Both halves of this answer are wrong — yen depreciation makes Swedish goods cost more, not less.
🔗 Review: Re-read "Reading the Units Carefully" and Worked Example 4. The single most important habit: always identify what's in the numerator and what's in the denominator before deciding direction.
4. If a nation's currency appreciates relative to that of its trading partners, what will happen to the nation's exports, imports, and aggregate demand?
✓ Correct answer: (C)
This is the classic appreciation→trade→AD chain. When a country's currency appreciates: (1) Foreigners must spend more of their own currency to buy the country's exports, so the country's exports become more expensive to foreigners → exports fall. (2) Domestic residents pay less of their own currency to buy foreign goods, so imports become cheaper → imports rise. (3) Net exports (X − M) fall. Since net exports are a component of aggregate demand, AD falls (shifts left). Three correct movements, all driven by the SPICE intuition: Strong currency → Imports Cheap, Exports Expensive.
Why the other options miss the mark
- (A) Exact reverse of correct. Appreciation reduces exports and raises imports, not the other way around.
- (B) Both exports and imports moving up is internally inconsistent for an appreciation shock — exports must fall.
- (D) Imports rise, not fall, under appreciation (cheaper foreign goods).
- (E) Exports fall (correct on AD direction, but wrong on exports/imports direction).
🔗 Review: Re-read "Why the Trade Effects Go the Way They Do." The full 6-step iPhone/Toyota story shows why each variable moves the direction it does.
5. Suppose the exchange rate moves so that the United States dollar appreciates against the Japanese yen. Which of the following best describes the simultaneous effect on the yen?
✓ Correct answer: (B)
This is the mirror rule. An exchange rate is a ratio between two currencies, so any movement in the rate is the same event described from either side. If the dollar appreciates against the yen, that means it takes more yen to buy a dollar — and equivalently, each yen now buys fewer dollars than before. The yen has depreciated against the dollar. There's no third possibility, no independence, no policy intervention required. It's a single fact described from two perspectives.
Why the other options miss the mark
- (A) Logically impossible. Two currencies cannot both appreciate against each other — appreciation is defined relative to another currency.
- (C) The exchange rate is the relative price of the two currencies; if one moves, the other has to move in the opposite direction by definition.
- (D) The yen's movement against other currencies (euro, pound, etc.) isn't determined by what happens to the dollar-yen rate alone. This option overreaches.
- (E) The mirror rule doesn't require any central bank action. It follows from arithmetic — the exchange rate is one number describing both directions at once.
🔗 Review: Re-read "The Mirror Rule." The single insight: every exchange-rate movement is two events — one currency appreciates, the other depreciates, by definition. They are not independent.
Ready for more? Take the full Unit 6 Practice Test →
End of Section 6.2. Up next: 6.3 The Foreign Exchange Market — the supply-and-demand model that determines exchange rates, and the most-tested graph in Unit 6.