Analysis of information sources in references of the Wikipedia article "List of countries by GDP (PPP)" in Simple English language version.
Although the EU is not a federation in the strict sense, it is far more than a free-trade association such as ASEAN, NAFTA, or Mercosur, and it has certain attributes associated with independent nations: its own flag, currency (for some members), and law-making abilities, as well as diplomatic representation and a common foreign and security policy in its dealings with external partners. Thus, inclusion of basic intelligence on the EU has been deemed appropriate as a new, separate entity in The World Factbook.