ABSTRACT
The renewed interest in economic development since the war has brought back into the literature an emphasis on the importance of technological change that was sadly lacking before the war. To a large extent diffusion of technology between countries is rather like diffusion of technology over an industry in which there are firms of very different types. The modern treatment of invention comes very close to that of Adam Smith who treated it exactly like other elements in division of labour and hence as limited by the size of the market. The scale on which American business has invested in the United Kingdom is in itself an indication that this is still an attractive location for economic activity and that there are decided conveniences in producing here. The more one reflects on technological diffusion the more apparent it is that it responds to much the same forces as govern economic efficiency.
