Purchasing Power Parity (PPP)
Quick Definition
An economic theory that compares currencies based on how much a standardized basket of goods costs in each country.
What Is Purchasing Power Parity (PPP)?
Purchasing power parity (PPP) is a theory stating that exchange rates should adjust so that identical goods cost the same in different countries when expressed in a common currency. In its absolute form, PPP implies that a basket of goods costing $100 in the U.S. should cost the equivalent in any other country after currency conversion. In practice, PPP rarely holds exactly due to transportation costs, tariffs, taxes, non-traded goods, and market imperfections, but it serves as a useful long-term anchor for exchange rate analysis. The most famous PPP application is The Economist's Big Mac Index, which compares the price of a McDonald's Big Mac across countries to assess whether currencies are over- or undervalued. PPP-adjusted GDP is widely used by the World Bank and IMF for comparing living standards across countries, as it accounts for price level differences — China's GDP is larger than the U.S. on a PPP basis despite being smaller in nominal terms, because goods and services are cheaper in China.
Purchasing Power Parity (PPP) Example
- 1The Big Mac Index shows a burger costs $5.69 in the U.S. but only $3.20 equivalent in China, suggesting the yuan is undervalued by about 44% versus PPP
- 2India's nominal GDP ranks 5th globally, but on a PPP basis it ranks 3rd, reflecting the lower cost of goods and services domestically
Related Terms
GDP Per Capita
A country's total economic output divided by its population, used as a measure of average living standards.
Exchange Rate Regime
The system a country uses to manage its currency's value relative to other currencies.
Real vs. Nominal Values
Nominal values are measured in current prices without inflation adjustment, while real values are adjusted for inflation to reflect actual purchasing power.
CPI (Consumer Price Index)
A measure of the average change in prices paid by urban consumers for a basket of goods and services, used as the primary gauge of inflation.
Interest Rate Parity (IRP)
An economic theory stating that the difference in interest rates between two countries equals the expected change in exchange rates between their currencies.
GDP (Gross Domestic Product)
The total monetary value of all finished goods and services produced within a country's borders in a specific time period.
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