Changes in a country's policy or market interest rates shift the relative returns available to domestic and foreign investors, and that shift is a primary driver of short- and long-term movements in exchange rates. At their simplest, higher domestic interest rates make assets denominated in that currency more attractive, increasing demand for the currency and tending toward exchange rate appreciation. Conversely, rate cuts typically reduce foreign demand and can lead to currency depreciation.
Transmission channels
The principal mechanism is the interest rate differential between countries. If investors can earn a higher yield on government bonds or deposits in Country A than in Country B, they will seek to buy assets in Country A, which requires purchasing its currency. This flow of capital exerts upward pressure on Country A’s currency. This dynamic underlies the theoretical frameworks of covered interest parity and uncovered interest parity, which connect forward exchange rates, expected spot rates, and interest differentials. Bank for International Settlements research documents how deviations from parity arise when funding costs or risk premia change, especially after the 2008 financial crisis Bank for International Settlements.
Expectations matter: markets price not only current rates but anticipated future policy. Maurice Obstfeld University of California Berkeley and colleagues have emphasized that forward-looking monetary policy and credibility shape exchange rate responses over time. A short-lived, unexpected rate hike may trigger a sharp, temporary appreciation, while a well-signaled, permanent change will be incorporated more gradually.
Causes, frictions, and empirical realities
Empirical studies by International Monetary Fund economists show that the theoretical one-to-one link between rate changes and exchange rates is often attenuated by frictions. Capital controls, market liquidity, banking sector health, and global risk sentiment all mediate the pass-through from interest rates to currency values. For example, when risk appetite falls, investors may prefer safe-haven currencies regardless of interest differentials; conversely, carry trades amplify currency movements when risk premia compress. Ben S. Bernanke Princeton University has written about how global capital flows and saving-investment imbalances shape exchange rates beyond pure interest-rate incentives.
These frictions mean that interest rate policy has distributional and territorial consequences. For small open economies reliant on exports, appreciation following rate hikes can harm manufacturers and exporters in coastal industrial regions, reducing employment and local tax bases. For low-income households, depreciation driven by rate cuts may raise import prices and inflation, squeezing purchasing power. Commodity-exporting countries experience additional complexity as global commodity prices interact with both interest-rate and exchange-rate channels.
Policy implications and consequences
Central banks balance the trade-off between stabilizing inflation and influencing the exchange rate. A tighter policy that appreciates the currency may help contain imported inflation but can weaken competitiveness and slow growth. The International Monetary Fund finds that policy credibility and communication are essential to moderate exchange-rate volatility and to avoid unintended consequences for public debt denominated in foreign currencies. For countries with large foreign-currency debts, even modest depreciations can sharply raise servicing costs, with fiscal and social ramifications.
In practice, interest rate shifts are a powerful but imperfect tool for influencing currency values. Their effects unfold through capital flows, expectations, and institutional frictions, producing outcomes that vary across countries, sectors, and social groups.