Technical Progress and the North-South Terms of Trade

In a classical world where prices of both northern manufactures and southern raw materials are determined by market demand and supply, technical progress in one region leads to a terms-of-trade improvement of the other region irrespective of whether technical progress is labor-saving or raw-material saving. But in a neo-Kaleckian framework characterized by surplus capacity, and an effective demand problem in the North and a capacity constraint in the South, the terms of trade would turn against the South even if the North experienced a higher rate of technical progress than that of the South