What is another word for customs unions?
Pronunciation: [kˈʌstəmz jˈuːni͡ənz] (IPA) 
Customs unions are a form of economic integration between countries, where members agree to eliminate trade barriers among them while maintaining a common external tariff. Synonyms for customs unions include trade bloc, free trade area, economic union, regional integration, common market, and customs alliance. These terms are often used interchangeably, but each has its own specific features, such as the depth of economic integration, the level of coordination in macroeconomic policies, and the scope of mutual recognition of goods and services standards. While customs unions aim to promote free trade and economic growth among members, they can also create trade diversion and political dependencies on the most powerful member states.
