The subsequent types of trading blocs have the following definitions:
Free Trade Area -- free trade among members
Customs Union -- free trade among members and common external tariff
Common Market -- free trade among members, common external tariff, and free movement of factors of production
Economic Union -- free trade among members, common external tariff, free movement of factors of production, and harmonization of all economic policies
What are some real-world examples of these different types of trading blocs?