How to Calculate Rer Real Exchange Rate

The Real Exchange Rate (RER) measures the true purchasing power of one currency relative to another, accounting for price differences in goods and services. Unlike the nominal exchange rate, RER adjusts for inflation in both countries, providing a more accurate comparison of living standards.

What is the Real Exchange Rate (RER)?

The Real Exchange Rate (RER) is a key economic indicator that shows how much of one country's goods and services can be purchased with one unit of another country's currency, after adjusting for price differences. It differs from the nominal exchange rate because it accounts for inflation in both countries.

RER is important for:

Comparing living standards between countries
Analyzing trade competitiveness
Understanding the true impact of exchange rate changes
Evaluating international price parity

While the nominal exchange rate shows the price of one currency in terms of another, RER provides a more accurate picture of purchasing power by removing the effects of inflation.

How to Calculate RER

Calculating the Real Exchange Rate involves several steps to account for price differences between countries. The most common method uses the following components:

Nominal exchange rate (current market rate)
Price level indices for both countries
Weighting factors for goods and services

The calculation process typically involves:

Obtaining current price indices for both countries
Converting the nominal exchange rate to a real exchange rate
Adjusting for the relative importance of different goods

RER Formula

The basic formula for Real Exchange Rate is:

RER = (Nominal Exchange Rate) × (Price Level Index of Country A / Price Level Index of Country B)

Where:

Nominal Exchange Rate = Current market exchange rate
Price Level Index = Measure of price changes in goods and services

Worked Example

Let's calculate the RER for the US dollar (USD) against the euro (EUR) using the following data:

Item	Value
Nominal Exchange Rate (USD/EUR)	0.85
Price Level Index (US)	120
Price Level Index (EU)	100

Using the formula:

RER = 0.85 × (120 / 100) = 1.02

This means that 1 USD can buy 1.02 EUR worth of goods and services after accounting for price differences.

In this example, the RER is higher than the nominal exchange rate, indicating that the US dollar has stronger purchasing power relative to the euro.

Interpreting RER Results

Understanding what RER results mean requires considering several factors:

RER > 1: The home currency has stronger purchasing power
RER = 1: Purchasing power is equal between currencies
RER < 1: The foreign currency has stronger purchasing power

Key interpretations include:

RER Scenario	Interpretation
RER > Nominal Exchange Rate	Home currency is appreciating relative to foreign currency
RER < Nominal Exchange Rate	Home currency is depreciating relative to foreign currency
RER = Nominal Exchange Rate	No real change in purchasing power

RER changes can indicate:

Changes in relative price levels
Shifts in trade competitiveness
Potential impacts on international trade

FAQ

What is the difference between nominal and real exchange rates?

The nominal exchange rate shows the price of one currency in terms of another without accounting for inflation. The real exchange rate adjusts for price differences between countries, providing a more accurate measure of purchasing power parity.

How often should I check the real exchange rate?

For business decisions, checking monthly is sufficient. For personal finance or international trade, quarterly updates provide a good balance between timeliness and stability.

Can RER be negative?

No, RER cannot be negative. It represents the relative purchasing power of one currency against another, which is always a positive value.