The OECD, Eurostat, and 47 participating countries work together in establishing purchasing power parities, or PPPs, in order to compare the price and volume levels of the GDPs. This programme is called the Eurostat-OECD PPP Programme. The manual gives a complete, detailed and up-to-date description of the functioning of the programme. This includes its organisation, the various surveys carried out by participating countries and the ways PPPs are calculated and disseminated. It also provides guidance on the use of PPPs.