Exchange rate regimes and their effects on trade and capital flows
No regime can deliver credibly fixed rates, full convertibility and independent monetary policy at once. Countries choose along a spectrum from giving up their own currency, through currency boards, pegs, target zones and crawling pegs, to managed or free floats. A trade deficit must be financed by an equal capital inflow, and capital flows drive exchange rates in the short to medium run.
Before this: Nominal vs real exchange rates
On the exam
- Describe exchange rate regimes and explain the effects of exchange rates on countries’ international trade and capital flows
Describe exchange rate regimes and explain the effects of exchange rates on trade and capital flows. Expect regime identification from a description (currency board versus fixed parity versus target zone), the impossibility of the ideal regime and the trade balance identity.
How deeply to learn each part
- Know the idea
- Understand it in general. It frames other topics, but you will not calculate with it.
- Use it
- Understand it well enough to solve a question with it. Recognize when it applies.
- Memorize
- Learn it by heart. The exam will not give it to you.
You know this one. The full lesson is folded away. The takeaways, formulas and checkpoint below are your quick refresher, and the checkpoint is a fair test of whether you still do.
You tested strong here. The full lesson is folded away. The takeaways, formulas and checkpoint below are your quick refresher, and the checkpoint is a fair test of whether you still know it.
Why can no currency regime be ideal?
Memorize
An exchange rate regime is the framework a country uses to manage its currency. The ideal currency regime would have three properties: exchange rates between any two currencies credibly fixed, all currencies fully convertible (so capital flows freely), and each country free to run its own monetary policy.
The three cannot coexist. If rates are credibly fixed and currencies fully convertible, there is in effect one world currency, and no country could influence interest rates or inflation by changing the supply of its own money. Independent policy is the one that has to go.
- Fixed rate and free capital Memorize gives up independent policy
- Examples currency board, dollarization, monetary union
-
- Fixed rate and own policy Memorize gives up free capital
- Needs capital controls to hold the peg
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- Free capital and own policy Memorize gives up the fixed rate
- Example a floating currency
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Why a peg removes independence. Suppose a pegged country cuts its interest rate below those abroad. Funds flow out in search of higher returns. The central bank has to sell foreign currency and buy its own to hold the peg, which shrinks the money supply and pushes rates back up, undoing the cut. Under a float the cut weakens the currency instead. That helps exports and reinforces the stimulus.
So the more freely a currency floats, or the tighter capital is controlled, the more independent the monetary policy. The cost is exchange rate risk and a less efficient allocation of capital.
What regimes exist?
Memorize
The regimes form a spectrum from no national currency at all to a fully market-set rate.
- No separate legal tender Memorize no national currency, no national monetary policy
- Dollarization Memorize uses another country's currency
- Monetary union Memorize shared currency and shared central bank
-
- Currency board Memorize legal commitment, monetary base fully backed by the anchor currency
- Fixed parity Memorize peg to a currency or basket, band up to ±1%, no legal commitment
- Target zone Memorize same idea, band up to ±2%
- Fixed parity with crawling bands Use it band widens on a set path, a gradual exit from the peg
-
- Crawling peg Memorize rate adjusted in small steps
- Passive crawl adjusted often to keep pace with inflation
- Active crawl pre-announced to steer inflation expectations
-
- Managed float Memorize intervenes to hit unannounced goals ("dirty float")
- Independent float Memorize market sets the rate; occasional intervention
| Regime | How it works | Monetary independence |
|---|---|---|
| No separate legal tender: dollarization | uses another country’s currency; imports its credibility, not its creditworthiness | none |
| No separate legal tender: monetary union | shared currency and shared central bank | shared, not national |
| Currency board | legal commitment to exchange at a fixed rate; monetary base 100% backed by the anchor currency; cannot be lender of last resort; earns seigniorage | almost none |
| Fixed parity | peg to a currency or basket, band up to ±1%; no legal commitment; reserves discretionary; can still be lender of last resort | limited; credibility depends on reserves |
| Target zone | fixed parity with a wider band (up to ±2%) | a bit more |
| Crawling peg | rate adjusted in small steps: passive (to match inflation) or active (pre-announced to steer expectations) | some |
| Fixed parity with crawling bands | band widens over time: a gradual exit from a peg | growing |
| Managed float | intervenes to hit unannounced internal or external goals (“dirty float”) | considerable |
| Independent float | market sets the rate; occasional intervention | full |
Three points separate the look-alikes on the exam:
- Currency board versus fixed parity. Only the board has a legal commitment and full backing. A parity can be adjusted or dropped, and its credibility rests on whether the market believes the reserves are enough. A belief that reserves are thin can start a speculative attack that drains them.
- Dollarization versus a currency board. A board keeps its own notes and earns seigniorage on the backing assets. Under dollarization that profit goes to the issuer of the currency used.
- Target zone versus crawling peg. A target zone has a fixed band. A crawling peg’s rate itself moves in small steps.
Why not just float? A country with a history of high inflation may lack the credibility to promise sound money under a float. Political goals matter too: the single currency was created partly to strengthen political union.
Go deeper How the dominant regime has changed
Know the idea
Before the First World War, major currencies were fixed to gold. A trade surplus brought gold in, expanded the money supply and lifted prices until exports cooled; a deficit worked the other way. After the Second World War the Bretton Woods system set fixed parities with occasional realignments, and it broke down in the early 1970s as inflation spread. Most developed economies have floated since, and the volatility that followed showed that investment flows, not trade, set exchange rates day to day. Europe went from a band system in the 1980s and 1990s to a single currency in 1999, giving up national monetary policy in the process.
Go deeper How a currency board's money supply moves
Know the idea
A board works like the classical gold standard. When foreign currency flows in, the monetary base expands, and when it flows out, the base contracts. Persistent one-way flows therefore show up as interest rate changes, not exchange rate changes.
Go deeper Why speculative attacks break pegs
Know the idea
If traders think reserves cannot cover sales of the currency, they sell it in size. That drains the reserves and can force an immediate devaluation, so the belief becomes self-fulfilling. This is why the level of reserves is the key issue for a simple fixed parity.
Go deeper Dollarized banks and anchor-country rates
Know the idea
Dollarized banks are not covered by the anchor country’s central bank or deposit insurance. Interest rates on the anchor currency in a dollarized economy therefore usually differ from those in the anchor country.
How do exchange rates link trade and capital flows?
Memorize
A country that imports more than it exports (a trade balance deficit) must pay for the difference by borrowing from foreigners or selling assets to them. That inflow is a surplus on the capital account . The two are always equal and opposite: anything that moves one moves the other.
The identity below shows this from the saving side.
Here X is exports, M imports, S private saving, I investment, T taxes net of transfers and G government spending. A trade surplus means the country saves more than it invests, so it lends the excess abroad. A deficit means saving falls short of investment, so it sells assets or borrows.
A country's private saving is 18% of GDP, investment is 22% and the government balance (taxes minus spending) is -3% of GDP. Its trade balance is closest to:
(18.00% − 22.00%) + (-3.00%) = -7.00%
Trade balance, X − M, % of GDP-7.00%
- 18−22+3+|-=−7
+|- change sign
- 18ENTER22−3CHS+−7
ENTER enter (on the HP, puts the number on the stack) · CHS change sign
Which adjusts first? Spending and goods prices change slowly, while asset prices and exchange rates change fast. So most adjustment happens in financial markets. Under a peg, the central bank absorbs the flows and interest rates adjust. Under a float, the exchange rate jumps. This is why capital flows are the main driver of exchange rates in the short to medium run; trade flows matter more in the long run.
Exam tip When the exam says “trade deficit”, write “capital account surplus” next to it before reading the options.
Memorize this
MemorizeThe regime ladder
| Regime | Key feature | Own monetary policy |
|---|---|---|
| Dollarization | another country's currency | none |
| Monetary union | shared currency and central bank | shared, not national |
| Currency board | legal commitment, 100% backing, no lender of last resort | almost none |
| Fixed parity | band to ±1%, no legal commitment, reserves discretionary | limited |
| Target zone | band to ±2% | a bit more |
| Crawling peg / bands | rate or band moves on a path | some, growing |
| Managed float | unannounced intervention | considerable |
| Independent float | market-set rate | full |
Memory hook Walk down the ladder: fewer promises to the market, more freedom at home. Bands: 0 (board), 1% (parity), 2% (zone).
Know it cold Only a currency board is a legal commitment. A fixed parity can be abandoned.
MemorizeTrade and capital flows
| Item | Statement |
|---|---|
| Identity | X − M = (S − I) + (T − G) |
| Deficit | trade deficit = capital account surplus (inflow) |
| Short to medium run | capital flows drive exchange rates |
| Long run | trade flows matter more |
Memory hook Trade deficit = capital account surplus: the deficit country pays by borrowing or selling assets.
Know it cold X − M = (S − I) + (T − G): deficit means saving falls short of investment, or the government runs a deficit.
- No separate legal tender Memorize no national currency, no national monetary policy
- Dollarization Memorize uses another country's currency
- Monetary union Memorize shared currency and shared central bank
-
- Currency board Memorize legal commitment, monetary base fully backed by the anchor currency
- Fixed parity Memorize peg to a currency or basket, band up to ±1%, no legal commitment
- Target zone Memorize same idea, band up to ±2%
- Fixed parity with crawling bands Use it band widens on a set path, a gradual exit from the peg
-
- Crawling peg Memorize rate adjusted in small steps
- Passive crawl adjusted often to keep pace with inflation
- Active crawl pre-announced to steer inflation expectations
-
- Managed float Memorize intervenes to hit unannounced goals ("dirty float")
- Independent float Memorize market sets the rate; occasional intervention
- Fixed rate and free capital Memorize gives up independent policy
- Examples currency board, dollarization, monetary union
-
- Fixed rate and own policy Memorize gives up free capital
- Needs capital controls to hold the peg
-
- Free capital and own policy Memorize gives up the fixed rate
- Example a floating currency
-
Quick example
Private saving is 15% of GDP, investment 19% and the government balance −1%. X − M = (15 − 19) + (−1) = −5% of GDP, a deficit financed by capital inflows.
- 15−19+1+|-= −5
+|- change sign
- 15ENTER19−1CHS+ −5
ENTER enter (on the HP, puts the number on the stack) · CHS change sign
How it is asked
-
Identify the regime
Law requires the central bank to issue local currency only against an equal value of euros held in reserve, at a fixed rate.
Currency board: legal commitment plus full backing. A crawling peg or managed float is the trap.
-
Impossible combination
Which combination of features can no regime deliver at the same time?
Credibly fixed rate, full convertibility and independent monetary policy together. Any two are possible; a peg with capital controls is the trap.
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Trade balance from saving and investment
Saving 20%, investment 23% and a government deficit of 2% of GDP. Trade balance?
(20 − 23) + (−2) = −5% of GDP. Adding the deficit as positive (−1%) is the trap.
-
Band width
A fixed band of up to ±2% around a parity is a:
Target zone. Up to ±1% is fixed parity.
Exam traps
- Thinking a fixed parity is more credible than a currency board. The board has the legal commitment and full backing.
- Saying a fixed parity means a perfectly constant rate. There is a band of up to ±1%.
- Confusing a target zone (fixed band) with a crawling peg (a moving rate).
- Saying a trade deficit country must buy foreign assets. It borrows from foreigners or sells them assets.
Checkpoint
4 exam-style questions. About 90 seconds each.
1A small economy's law requires its central bank to issue local currency only against an equal value of euros held in reserve, at a fixed rate. This regime is:
2Which combination of features can no exchange rate regime deliver at the same time?
3A country's private saving is 20% of GDP, investment 23% of GDP and the government runs a deficit of 2% of GDP. Its trade balance is closest to:
4A country's imports exceed its exports. Which statement is most likely correct?
Key takeaways
- Credibly fixed rate, free capital and independent policy cannot all hold. Choose two.
- Spectrum: dollarization or union, currency board, fixed parity, target zone, crawling peg or bands, managed float, independent float.
- A currency board has a legal commitment, full backing and no lender of last resort.
- X − M = (S − I) + (T − G). Capital flows drive exchange rates in the short to medium run.
Quick example
Private saving is 15% of GDP, investment 19% and the government balance −1%. X − M = (15 − 19) + (−1) = −5% of GDP, a deficit financed by capital inflows.
- 15−19+1+|-= −5
+|- change sign
- 15ENTER19−1CHS+ −5
ENTER enter (on the HP, puts the number on the stack) · CHS change sign
All Economics formulas, every lesson
Practice exam-style questions on Capital Flows and the FX Market
Questions about this lesson?
Where this comes back
- Capital restrictions: why governments limit capital flows Capital Flows and the FX Market
Questions candidates ask
What are the types of exchange rate regimes?
From the hardest peg to the freest float: no separate legal tender (dollarization or monetary union), currency board, fixed parity, target zone, crawling peg or crawling bands, managed float and independent float. Moving down the list, a country gains monetary independence.
What is the difference between a currency board and a fixed peg?
A currency board is a legal commitment to a fixed rate, with the monetary base fully backed by the anchor currency, so it cannot act as lender of last resort. A fixed peg has no such law, the central bank decides its reserves and can abandon the parity.
How is a trade deficit related to capital flows?
A trade deficit must be financed by an equal capital account surplus: the country borrows from foreigners or sells them assets. The identity X − M = (S − I) + (T − G) shows the same thing from the saving side.
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