Economics
Exchange Rates and Purchasing Power Parity
Quick fact
The Economist's Big Mac Index compares the price of a Big Mac across countries to estimate whether currencies are under- or over-valued relative to purchasing power parity.
Why this is interesting
You've likely seen that $10 can buy a hearty meal in some countries but just a coffee in others. Why does the money 'go further' in some places, and what does the exchange rate really tell us about value?