Trade Bloc Among Countries Located in the Same Region

A trade bloc is an agreement among countries located in the same region with the purpose of reducing or eliminating barriers to trade, (tariffs and non-tariff barriers). 

There are four major Trading Blocs: the European Union (EU), the Common Market of the South (MERCOSUR), the North American Free Trade Agreement (NAFTA) and the Association of Southeast Asian Nations (ASEAN). On top of that some other agreements exist such as The European Free Trade Association, Dominican Republic-Central America-United States Free Trade Agreement (CAFTA-DR), Latin American Integration Association and Common Market of Eastern and Southern Africa COMESA. 

Compare two trading blocs in terms of their nature (Free Trade Area, Customs Union or Common Market), similarities and differences, and the political and economic impact they have had in the last two decades. You may want to consider other blocs not listed here.