The wider discipline of trade theory within which we find the field of input-output economics consists of four broader areas. Input-output economics, based on the Heckscher-Ohlin theory and defined by the findings of Wassily Leontief forms the biggest most well known part. The Ricardian model, which is the next most important model to that on which input-output economics is based, will be described in some depth for the sake of comparison and to give an alternative insight into the discipline of trade theory.
The Ricardian model then, suggests that labor costs will be the determinant of trade: the country with the lower labor cost in the production of a good will be the exporter of that commodity. This theory was tested in 1952 by MacDougall who used data on 25 products from 1937 to compare labor productivity and exports for the United States and Great Britain. In this way, MacDougall tested whether their relative exports to third countries were connected with their labor productivities. The results which