In general terms, economic integration can be both beneficial and disadvantageous. On the one hand, it opens markets of member countries to member country firms, it allows firms to lower their average production and distribution costs, and it permits firms to become more competitive outside the trading bloc. Nevertheless it may also hurt some sectors of the economy because it exposes a firm's domestic market to competition from firms in other member countries, and thus less efficient firms can be threatened. .
In 1991, after several integration approaches between Argentina and Brazil , the Asuncion Treaty was signed by Argentina, Brazil, Paraguay, and Uruguay, and the MERCOSUR was created. The purposes of MERCOSUR include:.
Free transit of production goods, services and factors between the member states with inter alia, the elimination of customs rights and lifting of nontariff restrictions on the transit of goods or any other measures with similar effects; .
Fixing of a common external tariff (TEC) and adoption of a common trade policy with regard to nonmember states or groups of states, and the coordination of positions in regional and international commercial and economic meetings; .
Coordination of macroeconomic and sectorial policies of member states relating to foreign trade, agriculture, industry, taxes, monetary system, exchange and capital, services, customs, transport and communications, and any others they may agree on, in order to ensure free competition between member states; and .
The commitment by the member states to make the necessary adjustments to their laws in pertinent areas to allow for the strengthening of the integration process. The Asuncion Treaty is based on the doctrine of the reciprocal rights and obligations of the member states. MERCOSUR initially targeted free-trade zones, then customs unification and, finally, a common market, where in addition to customs unification the free movement of manpower and capital across the member nations' international frontiers is possible, and depends on equal rights and duties being granted to all signatory countries.