출처: Alan O. Ebenstein, Friedrich Hayek: A Biography (, ..)
Chapter 6. LSE
of which excerpt, pp. 53-54:
( ... ) Immediately before giving his early 1931 lectures at LSE, which were his introduction to the school, Hayek gave a one-lecture verion to the Keynes-dominated Marshall Society at Cambridge. Richard Kahn, one of Keynes's followers and later his literary executor, described the scene. Hayek had" a large audience of students, and also of leading members of the faculty. (Keynes was in London.) The members of the audienceㅡto a manㅡwere completely bewildered. Usually a Marshall Society talk is followed by a lively and protracted barrage of discussions and questions. On this occasion there was complete silence. I felt that I had to break the ice. So I got up and asked, 'Is it your view that if I went out tomorrow and brought a new overcoat, that would increase unemployment?" 'Yes,' said Hayek, 'But,' pointing to his triangles on the board, 'it would take a very long mathematical argument to explain why.'"
A basic difference between Hayek's and Keynes's approaches can be gathered from an interviw in which Hayek said that "I never believed or came to believe that there is a simple function between aggregate [demand] and employment. I insist that if you take the whole production as a stream, the earler parts of the stream can move to a great extent independently of what happens at the mouth of the stream. And on one occasion I almost got him[Keynes] to understand what I mean when I tried to explain to him that in certain circumstances an increase of the final demand will discourage investment because it became important to produce quickly even at higher cost, while a low demand will force investment to reduce costs. So the relation may be a decrease in demand stimulating investment and an increase in demand discouraging investment. For the moment he was very interested, and then he said, 'But that would be contrary to the axiom that employment depends on final demand. ...' Because this was so much an axiom in his life that there was a positive correlation between final demand and total employment, anything which conflicted with it was dismissed as absurd." 
Hayek's point was that, in the short run, increase in the demand for consumer goods can redirect production from longer temporal capital processes to the quick production of consumer goods, thereby entailing less capital investment in the longer temporal processes. This would discourage real investment.
Hayek's basic misconception of economic production was concerning the nature of capital. His essential practical thesis in technical economic theory was that artificially lowered interest rates misshape the structure of production by encouraging production of temporarily early capital goods. This thesis was based on Boehm-Bawerkian conception of capital wherein as an economy develops, production increasingly occurs through more and more "roundabout," or long and complex, processes.
Economic downturn was, in Hayek's view, the result of imbalance between an economy's ability to sustain development of longer capital productive processes and its ability to produce immediate consumer goods. In such a circumstances, buying a consumer good prevents the longer capital processes from being completed, thereby resulting in waste. He held in "The 'Paradox' of Saving" that if an "excessive extension of productive equipment has been once begun, and the impossibility of carrying it through has manifested itself in a crisis, the appearance of unemployment and the resulting diminution of the demand for consumption goods may be the only way to set free the means necessary to complete at least a part of the enlarged productive equipment."  Keynes, on the other hand, thought that Britain suffered from inadequate consumption and thus that any purchase was a step in the right direction. Robert Skidelsky remark of Hayek's views as put forward in his 1931 lectures that the 'contrasts with Keynes' 'Whenever you save five shillings you put a man out of work for a day' could not have been starker."