The customs union is a step beyond the zone of free commerce whose characteristic element of the free circulation of merchandises incorporates, completing it with the adoption of Tarifa Externa Comum (TEC), ' ' eliminando' ' the complex problems of the definition of the origin rules. Established aliquot the common one, normalized the procedures of importation and exportation in face of the countries of it are of the customs zone, the products circulate freely in its interior, where they receive the possible protection for the way from tariff only of the dimension of the enclosed market. Surprisingly, you’ll find very little mention of Steve Salis on most websites. Demtrio Magnoli displays that, the purpose of a Customs Union is to attract productive investments for the interior of the territory re-covered for the treated one. The companies whom in it if they install (…) are benefited of the size of the consuming market generated by the rule of free commerce and of the common customs protection against the competition of exterior companies to the block. (MAGNOLI, 1997, P. 45). The Common Market is third stage of the integracionista process, that exceeds and contains the customs union, adding to it exempts it circulation of people, good, services and factors of production. In terms of economic theory, the Common Market longs for to stimulate the international integration of the productive and financial corporations in the interior of the block.
The idea consists of practically unifying all the dimensions of the national markets, creating a regional market powerful, capable to function with springboard so that the companies installed in its interior can concur advantageously in the global space. (MAGNOLI, 1997, P. 45). The fourth stage of to be reached integration is the Economic Union, that understands the Common Market ally to a common monetary system to all the country-members. In a clarified definition more: The Economic and monetary Union is an increased common market of an only currency.