The real exchange rate (RER) measures how many units of foreign goods one unit of domestic goods can buy, stripping out the distortion caused by differing inflation rates between countries. It is typically expressed as:
RER = (Nominal Exchange Rate × Foreign Price Level) / Domestic Price Level
Unlike the nominal exchange rate, which only reflects the market price of one currency in terms of another, the RER captures competitiveness. If a country's RER appreciates, its goods become more expensive relative to foreign goods, often widening the trade deficit; a depreciation makes exports cheaper and imports dearer.
Economists use the RER to evaluate whether a currency is overvalued or undervalued relative to a benchmark such as purchasing power parity (PPP). The IMF publishes regular External Sector Reports assessing real effective exchange rates (REER) — a trade-weighted version measured against a basket of partner currencies — for major economies.
Key applications include:
- Trade policy analysis: Persistent RER misalignment is often cited in disputes over "currency manipulation," notably in U.S. Treasury semiannual reports to Congress.
- Development economics: The Balassa–Samuelson effect predicts that faster-growing economies experience real appreciation as productivity in tradable sectors rises.
- Crisis diagnostics: Sharp real overvaluation preceded several emerging-market crises, including Argentina's 2001–2002 collapse and the 1997 Asian financial crisis.
A common policy debate concerns whether countries should target a competitive (undervalued) RER to promote export-led growth, as some scholars argue China did through much of the 2000s. Critics counter that sustained undervaluation imports inflation and provokes trading-partner retaliation.
The RER is not directly observed in markets; it is a constructed index. Different choices of price deflator — consumer price index, producer price index, or unit labor costs — yield meaningfully different readings, so careful methodological disclosure matters when citing RER figures in research.
Example
In its 2023 External Sector Report, the IMF assessed that several G20 economies' real effective exchange rates were broadly in line with fundamentals, while flagging persistent misalignments in a handful of surplus and deficit countries.
Frequently asked questions
The nominal rate is the market price of one currency in another; the real rate adjusts that figure for differences in domestic and foreign price levels, reflecting actual purchasing power and trade competitiveness.
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