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Fixed vs Floating Exchange Rates: Two Currency Regimes
Every country has to decide who sets the price of its currency. A fixed regime hands that job to the government, which promises to trade at a set rate and defends it. A floating regime hands it to the market, where supply and demand move the price minute by minute. The choice shapes inflation, interest rates, and how a country weathers a crisis.
Key Takeaways
- A fixed exchange rate (a peg) commits the central bank to buy or sell its currency at a set price, which it must defend by spending foreign-currency reserves.
- A floating exchange rate lets the market set the price freely, so the currency absorbs shocks through its value rather than through the central bank's reserves.
- Fixed regimes deliver price stability and low inflation but surrender independent monetary policy and can break violently when reserves run out.
- Floating regimes keep policy flexibility and rarely suffer reserve crises, but they tolerate day-to-day volatility that importers, exporters, and travelers must manage.
Key Takeaways
- A fixed exchange rate (a peg) commits the central bank to buy or sell its currency at a set price, which it must defend by spending foreign-currency reserves.
- A floating exchange rate lets the market set the price freely, so the currency absorbs shocks through its value rather than through the central bank's reserves.
- Fixed regimes deliver price stability and low inflation but surrender independent monetary policy and can break violently when reserves run out.
- Floating regimes keep policy flexibility and rarely suffer reserve crises, but they tolerate day-to-day volatility that importers, exporters, and travelers must manage.
What It Is
A fixed exchange rate is a rate the government or central bank pins to a chosen anchor, usually a major currency such as the US dollar or the euro, and sometimes a basket. The authority publishes the target and stands ready to trade at it. Hong Kong, Saudi Arabia, and Denmark run long-standing pegs of this kind.
A floating exchange rate has no official target. The price is whatever buyers and sellers agree to in the open market at any moment. The US dollar, the euro, the yen, and the British pound all float. In practice most "floats" are managed to some degree, meaning the central bank occasionally intervenes to smooth swings without defending a fixed number.
The Intuition
Think of a currency's price like any other price. Under a float, the price is free to move, so an imbalance between buyers and sellers is cleared instantly by the rate itself. Under a peg, the price is frozen, so the imbalance has to be absorbed somewhere else - and that somewhere is the central bank's stockpile of foreign reserves. The bank becomes the buyer or seller of last resort at the promised rate. That works only as long as the reserves hold out. A float never runs out of price to give; a peg can run out of reserves.
How It Works
To hold a peg, the central bank meets any excess demand or supply at the target rate. If everyone is selling the local currency, the bank buys it back using its reserves of foreign currency, propping up the price. If everyone is buying, the bank sells local currency and accumulates reserves. Defending against selling pressure is the dangerous direction, because reserves are finite.
A floating rate needs no reserves to function. When capital flows out, the currency simply weakens until the cheaper price attracts new buyers, and the adjustment happens through the exchange rate rather than the reserve account. The cost is volatility and imported inflation when the currency falls.
There is a deeper constraint known as the impossible trinity: a country cannot simultaneously have a fixed exchange rate, free movement of capital, and an independent monetary policy. Pegging forces it to give up policy independence, because its interest rates must track the anchor country's.
Worked Example
A country pegs its currency at 20 pesos per US dollar and holds $30 billion in reserves.
Investors lose confidence and try to move 200 billion pesos out of the country. At the peg, that demands 200 / 20 = $10 billion of reserves. The central bank sells $10 billion to defend the rate, leaving 30 - 10 = $20 billion.
The outflows continue at roughly $10 billion per month. At that pace the remaining reserves are gone in about two more months. Rather than hit zero, the central bank abandons the peg and lets the currency float.
The market settles at 25 pesos per US dollar. A holder of pesos who could once get 1 / 20 = $0.050 per peso now gets only 1 / 25 = $0.040 per peso, a 20% loss in dollar terms. For an importer, goods invoiced at $1,000,000 that used to cost 20,000,000 pesos now cost 25,000,000 pesos, a 25% rise in local-currency terms. The peg postponed the adjustment; it did not prevent it.
Common Mistakes
- Believing a peg removes risk. It only hides the risk until reserves run low, at which point the adjustment arrives all at once as a devaluation rather than gradually.
- Confusing a peg with a currency board. A currency board backs the entire monetary base with reserves by law, a far stricter arrangement than a discretionary peg.
- Assuming floating means the central bank does nothing. Most floats are managed, with occasional intervention to smooth disorderly moves.
- Ignoring the policy cost. Under a credible peg, the country imports the anchor country's interest-rate stance and loses the ability to set rates for its own economy.
- Treating reserves as unlimited. A determined speculative attack can exhaust even large reserve stocks quickly, as several historical crises have shown.
Frequently Asked Questions
Q: What is the difference in a fixed vs floating exchange rate? Under a fixed exchange rate the central bank promises a set price and defends it with foreign reserves, while under a floating exchange rate the open market sets the price and the rate adjusts freely to supply and demand.
Q: Is a fixed vs floating exchange rate better for controlling inflation? A credible fixed rate anchored to a low-inflation currency can import that stability and hold inflation down. A floating rate gives no automatic anchor, so inflation control depends on the central bank's own policy.
Q: What role do reserves play in a peg? Reserves are the ammunition a central bank uses to defend a fixed rate. When the currency is under selling pressure, the bank spends reserves buying it back. If reserves run out, the peg breaks.
Q: Can a country switch between fixed and floating? Yes. Countries move along a spectrum from hard pegs through managed floats to free floats, and they change regimes over time, often floating after a peg becomes too costly to defend.
Q: Which major currencies float? The US dollar, euro, Japanese yen, and British pound are all floating currencies. Pegged examples include the Hong Kong dollar and the Saudi riyal, both tied to the US dollar.
Sources
- Investopedia. "Fixed Exchange Rate." https://www.investopedia.com/terms/f/fixedexchangerate.asp
- Investopedia. "Floating Exchange Rate." https://www.investopedia.com/terms/f/floatingexchangerate.asp
- Investopedia. "Currency Peg." https://www.investopedia.com/terms/c/currencypeg.asp
- International Monetary Fund. "Annual Report on Exchange Arrangements and Exchange Restrictions (AREAER)." https://www.imf.org/en/Publications/Annual-Report-on-Exchange-Arrangements-and-Exchange-Restrictions
Disclaimer
This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.