1. 1. The 70-75 per cent figure is the official Soviet estimate and must be viewed as no more than an approximation . Narodnoe Khoziaistvo SSSR v 1965 g. (Moskva, 1966 ), p.85 .
2. 1. The method employed in calculating the relative agricultural output of the USSR and United States is not explained . The extent to which double counting of agricultural products such as livestock feeds has been avoided is not known . The percentage relationship, moreover, would vary at least moderately depending on the price system used in the calculations. For example, if there were a greater spread between the price of a pound of wheat and a pound of meat in the Soviet Union than in the United States, the latter, with a greater emphasis on meat production, would show up better if Soviet prices were used to calculate the comparative output of all farm commodities in the two countries. The USSR, under the same conditions, would have an agricultural output closer to that of the United States if the latter's prices were employed. The calculated spread in the relative industrial production of the two nations varies substantially, depending on whether rouble or dollar values are used in the analysis. This can be attributed to the combined effect of an unusually heavy emphasis on producers' goods in the Soviet industrial economy and to the artificially high prices which have been set for consumers' goods. Although the farm economies of the two nations also differ in terms of the relative emphasis on specific products or groups of products, there is little evidence to suggest that the price structures vary as greatly or as consistently as they do in the industrial sector. For the purposes of this paper, where an approximation will suffice, the Soviet estimate of relative output would appear adequate.
3. 2. With a cropland base almost one-quarter as large as the United States, the total value of farm products sold by Canadian farmers is not quite one-tenth that of their American counterparts . In fact, both California and Iowa have a farm income not substantially below that of Canada as a whole . Even without adjusting for the lower value of the dollar, income per acre in Canada has averaged less than half the United States level. On the other hand, if American farm commodity prices were employed to calculate Canada's agricultural output, and if allowance were made for a higher rate of double counting of agricultural commodities in the American farm economy in the form of purchased feed and livestock, the spread in agricultural output would be somewhat reduced. It is unlikely, however, that the productivity of Canada's arable land relative to that of the United States would exceed the 50 per cent level suggested in this paper.
4. 3. The relative productivity of Canada's agricultural land resource would compare more favourably with that of the Soviet Union if agricultural output were calculated per acre of land actually devoted to crops rather than per acre of cropland . In Canada over 35 per cent of the cropland recorded in the 1961 Census was devoted to fallow and improved pasture . In the Soviet Union only about 10 per cent of the cropland is so used. In the United States the proportion in 1959 was about 30 per cent. Although seeded pasture might be viewed as a crop comparable to hay, fallow contributes only in a very indirect sense to agricultural output. Mention should also be made of the fact that comparisons of land productivity in this paper are based on the relationship between agricultural output and the cropland resource, without allowance for differences in the acreage of natural pasture land employed in the farm economy. It is impossible to isolate that fraction of agricultural output that is derived from lands in the latter category, but it would not be substantial. Moreover, as noted in the introduction, the total acreage of unimproved grazing land employed by collective and state farms in the USSR is fairly comparable to the combined total for the United States and Canada.
5. 4. The ratios have been calculated by dividing the total arable acreage in collective farms, including land in private garden plots, for each of the official economic planning regions of the USSR by the total number of collective farm households reported for each region . The data are for 1964 and are derived from statistics inNarodnoe Khoziaistvo SSSR v. 1964 g. (Moskva, 1965 ), pp.264 , 402 .