The Organisation for Economic Co-operation and Development is an intergovernmental organisation with 38 member countries, founded in 1961 to stimulate economic progress and world trade. It is a forum whose member countries describe themselves as committed to democracy and the market economy, providing a platform to compare policy experiences, seek answers to common problems, identify good practices, and coordinate domestic and international policies of its members.
The majority of OECD members are generally regarded as developed countries, with high-income economies, and a very high Human Development Index.
As of 2024 their collective population is 1.38 billion people with an average life expectancy of 80 years and a median age of 40, against a global average of 30. As of 2017, OECD Member countries collectively comprised 62.2% of global nominal GDP and 42.8% of global GDP at purchasing power parity. The OECD is an official United Nations observer. OECD nations have strong social security systems; their average social welfare spending stood at roughly 21% of GDP.