He served as a go-between for Roosevelt and Stalin in 1944 (post Second World War) and as the Polish ambassador to the US from 1945-1946. In 1946, Lange served as the Polish delegate to the United Nations Security Council. A major part of his contribution to economics came during his stint in the US (1933-1945).
Although a socialist to the core, he was not a great supporter of Marxian labor theory of value, and instead believed in the neoclassical theory of price (http://cepa.newschool.edu/het/profiles/lange.htm).
In this paper, I will actually make an attempt to highlight various things that will make the topic of the place of interest in production theory a bit clearer to the readers. There are a number of things that can be learnt from the production theory. Among these things, some of the important ones are the basics that surround the production theory. These are the basics that will put the discussion of the topic into a definite perspective.
In his paper, Lange has tried to give an explanation of the foundation of the existing Theory of Interest . He has actually tried to restate some fundamental propositions of the existing Theory of Interest by making special reference to the General Theory of Production. ...