Transition economy to the IMF, Iran is in transition to a market economy, demonstrating early stages of a transition economy. The eight first-wave accession countries, which joined the European Union on 1 May 2004 (Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia, Slovenia) and the two second-wave accession countries that joined on 1 January 2007 (Romania and Bulgaria) have completed the transition process. According to the World Bank, "the transition is over" for the 10 countries that joined the EU in 2004 and 2007. It can be also understood as all countries of the Eastern Bloc. "Transition economics" is a special branch
Withdrawal from the European Union occur on 29 March 2019. Three territories of EU member states have withdrawn: French Algeria (in 1962, upon independence), Greenland (in 1985, following a referendum) and Saint Barthélemy (in 2012), the latter two becoming Overseas Countries and Territories of the European Union. Article 50, which allows a member state to withdraw, was originally drafted by Scottish cross-bench peer and former diplomat Lord Kerr of Kinlochard, the secretary-general of the European Convention, which drafted the Constitutional Treaty for the European Union. Following the failure of the ratification process for the European Constitution, the clause was incorporated into the Treaty of Lisbon