Real Effective Exchange Rate (REER)

Real Effective Exchange Rate (REER)

The REER tells you what a currency is worth against a weighted basket of trading-partner currencies once you account for differences in inflation. The underlying identity is REER = NEER × (CPI_domestic / CPI_foreign), where NEER is the nominal effective exchange rate. When the REER climbs, the currency is buying more abroad in real terms, so exports get pricier and imports get cheaper. When it drops, the country is winning back external competitiveness.

The Banco Central do Brasil runs a REER index off a 13-currency basket (USD, EUR, CNY, ARS, MXN, JPY, GBP, KRW, INR, CAD, CHF, AUD, CLP) weighted by trade flows, while the IMF, BIS and ECB publish wider indexes spanning 40–60 currencies. The figures are quoted relative to a base year (BCB uses 2010 = 100). Once the REER sits 20% above its long-run average, that's the classic textbook signal that exporters are losing ground, and it tends to show up ahead of a currency adjustment.

Applications

Central banks treat the REER as a misalignment gauge, and the IMF Article IV consultations spell out whether they think a currency is overvalued. Exporters and importers lean on it to see margin pressure coming. Macro hedge funds short currencies once the REER runs 1–2 standard deviations above trend. The Economist's Big Mac Index is the playful, loose cousin of PPP, working out implied exchange rates from burger prices rather than full CPI baskets. Good for making a point, not for setting policy.

FAQ

Why REER instead of bilateral USD/BRL? A bilateral rate leaves out trade with China, Argentina, the EU and everywhere else. The REER folds the whole external competitive picture into one number.

What weights does the BCB use? Total trade (exports + imports), revised from time to time. China carries the largest weight right now (~25%), with the US and EU behind it.

Does a low REER guarantee export growth? No. It helps margins, but external demand, supply constraints and trade policy all weigh in. The 2015–2016 BRL collapse handed Brazil a competitive REER, yet exports rose only modestly because the rest of the world was slowing down.