Heckscher-Ohlin
According to this theory a country exports goods whose production uses intensively on the excess factor of production, and imports goods for the production of which she was the relative lack of production factors. Necessary conditions for existence:
1.From member countries of international exchange has tended to export those goods and services for the manufacture of which are primarily used factors of production available in abundance, and conversely, the tendency for import of the products for which there is a lack of any factors;
2.Development of international trade leads to equalization "factor" prices, that is, income generated from the owner of this factor;
3.There is a possibility, given sufficient international mobility of factors of production replaced the export of goods moving between the factors themselves.