Purchasing power parity (PPP) measures how much a currency can buy in terms of an international benchmark (usually dollars), since the cost of goods and services differs between countries. PPP is below the value of a US dollar in countries where the general price index is lower than in the US (as is the case for all five Caspian states, to varying extents), and above it where the prices are higher. A dollar thus buys much more in the Caspian countries than in the US, which only marginally compensates for the much lower income per person. These curves do not allow any conclusions on the wealth of individuals or income distribution among the population.
From collection: Vital Caspian Graphics 2 - Opportunities, Aspirations and Challenges, 2012
Philippe Rekacewicz (le Monde Diplomatique) assisted by Laura Margueritte and Cecile Marin, later updated by Riccardo Pravettoni (GRID-Arendal), Novikov, Viktor (Zoi Environment Network)