The Convention on the OECD was signed in Paris on 14 December 1960 when the Organisation for European Economic Co-operation (OEEC), formed in 1948 to administer aid under the Marshall Plan for the reconstruction of Europe after World War II, was reconstituted as the Organisation for Economic Co-operation and Development, "in order to strengthen the tradition of co-operation and apply it to new tasks and broader objectives".
The Convention came into force on 30 September 1961.
The Convention is complemented by:
Thirty four countries are now party to the Convention, the twenty "founder" Members and a further fourteen who have subsequently become Members.
Declarations by certain Member countries
Some countries have made "Declarations" concerning principally the territorial application of the OECD Convention.