DEFINITION of 'Purchasing Power Parity-PPP'. An economic theory that estimates the amount of adjustment needed on the exchange rate between countries in order for the exchange to be equivalent to each currency's purchasing power.
Thomas Edison's most famous invention, the lightbulb, paved the way for modern life.
Thomas Edison is famous for his lightbulb, but he never won a Nobel Prize. The 2014 Nobel Prize in physiology or medicine has gone to three scientists who discovered brain cells that help us stay orientedâour inner GPS..