If South America were to unite as one country would they become an economic superpower? Often borders can hold back different parts of the world and if they consolidated together they could succeed so much more. What would be the pros and cons If South America were to break down their borders and develop together as one country?  

Would this make Soth America a superpower and a leading country in GDP?
In answer to the narrower question of how significant an economy South America would be, here's a rough comparison of current (2016) GDP:



The Caribbean is included in Latin America for good measure (and because that's the way the World Bank cut up the data).  The US is 3.5 times the size, the EU 3.1 times, and China 2.1 times.  The economic area would be almost 3 times the size of the Brazilian economy.

In terms of pros and cons, there are probably larger political than economic issues involved.

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