Fixed vs. Floating Exchange Rates: How the Two Systems Compare

How a Floating Rate Works

Under a floating regime, a currency’s value is set by supply and demand in the foreign exchange market, with no official target. Demand comes from foreigners buying the country’s exports and its financial assets; supply comes from residents buying foreign goods and assets. The rate moves continuously, and that movement is the adjustment mechanism: a country whose external position deteriorates sees its currency depreciate, which makes its exports cheaper abroad and tends to restore balance without requiring domestic wages or prices to fall. Most large economies have floated since the early 1970s, though many practice “managed” floating, intervening occasionally to smooth disorderly moves.

How a Fixed Rate Works

Under a fixed or pegged regime, the government commits to holding the currency at a declared rate against another currency or a basket. Maintaining that promise requires action: when downward pressure appears, the central bank sells foreign reserves to buy its own currency, or raises interest rates to attract capital, or restricts capital movement. Variants sit along a spectrum of hardness — an adjustable peg like Bretton Woods, a crawling peg that moves on a schedule, a currency board that backs domestic money with foreign reserves at a fixed rate (Hong Kong has operated one since 1983), and full monetary union or dollarization, where a separate currency ceases to exist.

The Trade-offs

Fixed rates deliver predictability. Exporters, importers, and cross-border investors can plan without hedging currency risk, transaction costs fall, and a peg to a low-inflation anchor can import monetary credibility for a country with a poor inflation record. The cost is that all adjustment must run through the domestic economy: when a shock hits, prices, wages, and employment move instead of the exchange rate. Floating rates reverse the bargain. They absorb shocks through the currency and preserve an independent monetary policy able to respond to domestic conditions, at the price of volatility, hedging costs, and exposure to swings driven by speculation rather than fundamentals.

The Impossible Trinity

The constraint that organizes this whole choice comes from Robert Mundell and Marcus Fleming: a country can have at most two of three things — a fixed exchange rate, free movement of capital across its borders, and a monetary policy set for domestic conditions. Choose a fixed rate with open capital markets, and interest rates must be whatever defending the peg requires. Choose a fixed rate with independent monetary policy, and capital controls become necessary. Choose independence and open capital markets, and the exchange rate has to float. Every regime in modern history can be located by which corner of this triangle it gives up.

Historical Examples

The classical gold standard of roughly 1870 to 1914 and the Bretton Woods system of 1944 to 1971 were the two great fixed-rate regimes, and both ultimately broke under the strain of defending parities. Since 1973 the major currencies have floated against one another. Europe took the opposite path, moving from the Exchange Rate Mechanism launched in 1979 — from which sterling was forced out in September 1992 — to full monetary union, with the euro introduced as an accounting currency in 1999 and as notes and coins in 2002. Many smaller economies still peg, and Hong Kong’s currency board has operated since 1983.