Foundationsinternational trade
Exchange Rates: Prices Between Currencies
Overview
An exchange rate is the price of one currency in terms of another: how many yen per dollar, how many dollars per euro. These prices move constantly, shaping export competitiveness, import costs, tourism, investment returns, and inflation. This lesson covers how rates are quoted, what appreciation and depreciation mean (and for whom they help or hurt), and the core drivers — interest rates, inflation, growth, and expectations — plus the difference between nominal and real exchange rates.
Learning objectives
- Quote and interpret exchange rates in both directions
- Distinguish appreciation from depreciation
- Explain who gains and loses from currency moves
- Identify the main drivers of exchange rates
- Distinguish nominal from real exchange rates
Reading an exchange rate
Rates are quoted as pairs: USD/JPY 150 means one US dollar buys 150 Japanese yen; EUR/USD 1.08 means one euro buys 1.08 dollars. The first currency is the base, the second the quote. Note the direction trap: when USD/JPY rises from 140 to 150, the dollar strengthened (buys more yen) and the yen weakened. When EUR/USD rises, the euro strengthened. Always ask 'how many units of the quote currency per one unit of base?' before judging who appreciated. Spot rates are for immediate exchange; forward rates lock in a future exchange, letting firms hedge currency risk.
If the number rises, the base currency appreciated and the quote currency depreciated. State which currency you mean — 'the yen fell' and 'USD/JPY rose' say the same thing.
Appreciation and depreciation: winners and losers
When a currency appreciates, imports get cheaper (good for consumers and importers, and it dampens inflation) but exports get pricier for foreigners (bad for exporters and import-competing firms). Depreciation does the reverse: exports cheaper abroad, imports pricier at home, and imported inflation rises. There is no universally 'good' direction — it depends on whether you buy foreign goods or sell abroad. Governments sometimes welcome depreciation to boost exports, while central banks fighting inflation may welcome appreciation.
Depreciation = market-driven fall. Devaluation = deliberate cut of a fixed peg by the government. Same direction, different mechanism.
What moves exchange rates
Four forces dominate. Interest-rate differentials: higher domestic rates attract capital inflows seeking yield, bidding up the currency (the carry trade). Inflation differentials: persistently higher inflation erodes purchasing power and typically weakens the currency over time. Growth and trade flows: strong growth attracts investment; trade surpluses mean foreigners need your currency to buy your goods. Expectations and risk sentiment: in crises, capital flees to 'safe havens' (dollar, Swiss franc, yen) regardless of fundamentals. Central bank intervention — buying or selling currency — can move rates short-term but rarely defeats fundamentals for long.
Day-to-day moves are dominated by news, sentiment, and speculation. Fundamentals explain trends over months and years, not Tuesday's wiggle.
Nominal vs. real exchange rates
The nominal rate is the market quote. The real exchange rate adjusts for price levels: real = nominal × (domestic prices ÷ foreign prices). It measures true competitiveness — how many foreign goods one unit of domestic goods buys. If the nominal rate is flat but domestic inflation runs 10% above foreign inflation, the real rate appreciates 10%: your goods got 10% pricier abroad even though the quote didn't move. Economists watch real effective exchange rates (trade-weighted against many partners) as the summary gauge of competitiveness. Persistent real appreciation without productivity gains signals trouble for exporters.
Fixed, floating, and managed
Regimes matter for how rates move. Free floats (dollar, euro, yen) let markets set the rate. Pegs fix the rate to another currency (Hong Kong dollar to USD) — requiring the central bank to hold reserves and mirror the anchor's monetary policy. Managed floats (India, Singapore) let markets move the rate within bounds, intervening against disorder. Currency boards and dollarization are harder pegs still. Each regime trades off monetary independence against exchange-rate stability — the 'impossible trinity' says you cannot simultaneously have free capital flows, fixed rates, and independent monetary policy.
Key points
- An exchange rate is the price of one currency in another; quote direction determines who appreciated.
- Appreciation helps importers/consumers and hurts exporters; depreciation does the reverse.
- Interest rates, inflation, growth, and risk sentiment drive currency moves.
- The real exchange rate (price-adjusted) measures true competitiveness.
- Regimes range from free floats to hard pegs, each with trade-offs.
Common misconceptions
✓ Truth: Strength helps consumers and fights inflation but hurts exporters and tourism. The ideal rate depends on economic conditions — there is no universally best level.
✓ Truth: Under floating regimes markets set the rate; even pegs require massive reserves and policy sacrifice, and pegs regularly collapse under pressure.
✓ Truth: They feed into import prices, inflation, corporate profits, investment returns, and debt burdens — touching nearly every household.
Practice questions
Q1. USD/JPY moves from 140 to 155. This means:
- The yen appreciated
- The dollar appreciated (and the yen depreciated)
- Both currencies appreciated
- Nothing can be inferred
More yen per dollar means each dollar buys more yen — the dollar strengthened and the yen weakened. Always read the quote direction: base currency (USD) per quote (JPY).
Q2. A depreciation of the domestic currency tends to:
- Make exports more expensive for foreigners
- Make exports cheaper for foreigners and imports pricier at home
- Reduce inflation
- Have no effect on trade
Depreciation lowers the foreign-currency price of exports (boosting competitiveness) while raising the domestic price of imports — which can feed into inflation.
Q3. The real exchange rate differs from the nominal rate because it:
- Includes transaction fees
- Adjusts for differences in national price levels
- Is set by governments
- Only applies to tourists
Real = nominal × (domestic prices / foreign prices). It captures competitiveness: if domestic prices surge while the nominal quote is flat, the real rate appreciates.
Click a question to reveal the answer and explanation.
Frequently asked questions
Why did the yen weaken so much in 2022–2023?
The Bank of Japan kept interest rates near zero while the US Federal Reserve raised rates aggressively. The widening rate gap pulled capital toward dollars, selling yen — a textbook interest-differential move.
What is the 'impossible trinity'?
The principle that a country cannot simultaneously maintain free capital movement, a fixed exchange rate, and independent monetary policy — it must give up one. Most advanced economies chose floating rates plus monetary independence.
How do companies protect against currency swings?
Through hedging: forward contracts lock in future rates, options insure against adverse moves, and 'natural hedging' matches revenues and costs in the same currency.
What is a currency crisis?
A rapid, forced depreciation — often when a peg collapses under speculative attack or when foreign-currency debt becomes unpayable. Examples: Mexico 1994, East Asia 1997, Argentina 2001.