The Organisation for Economic Co-operation and Development (OECD; French: Organisation de coopération et de développement économiques, OCDE) is an intergovernmental economic organisation with 36 member countries, founded in 1961 to stimulate economic progress and world trade. It is a forum of countries describing themselves as committed to democracy and the market economy, providing a platform to compare policy experiences, seeking answers to common problems, identify good practices and coordinate domestic and international policies of its members. Most OECD members are high-income economies with a very high Human Development Index (HDI) and are regarded as developed countries. As of 2017, the OECD member states collectively comprised 62.2% of global nominal GDP (US$49.6 trillion) and 42.8% of global GDP (Int$54.2 trillion) at purchasing power parity. OECD is an official United Nations observer.In 1948, the OECD originated as the Organisation for European Economic Co-operation (OEEC), led by Robert Marjolin of France, to help administer the Marshall Plan (which was rejected by the Soviet Union and its satellite states). This would be achieved by allocating United States financial aid and implementing economic programs for the reconstruction of Europe after World War II. (Similar reconstruction aid was sent to the war-torn Republic of China and post-war Korea, but not under the name "Marshall Plan".)In 1961, the OEEC was reformed into the Organisation for Economic Co-operation and Development by the Convention on the Organisation for Economic Co-operation and Development and membership was extended to non-European states. The OECD's headquarters are at the Château de la Muette in Paris, France. The OECD is funded by contributions from member states at varying rates and had a total budget of €374 million in 2017.