The speed of Soviet industrial expansion during the Five Year Plans as measured by the rate of growth of industrial output has evoked keen interest and much controversy among Western observers of Soviet affairs. Soviet industrial development has attracted attention from abroad for three main reasons: i) because of the accompanying rise of the Soviet Union as a great international power, 2) as an example of a centrally controlled and directed economy in action, and 3) as a possible model for the economic development of backward areas. The source of controversy has been the uncertain accuracy of the statistical descriptions of Soviet economic development and especially industrial growth.
Official Soviet measures of industrial output are suspect for reasons connected with the technique of their construction. Until 1950, published statistics on aggregate Soviet industrial output were expressed in prices nominally of the crop year 1926-27.