1176 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 7 
The thirties was a period of adversity on agriculture — 
drought, low prices, low incomes — yet output increased 
more than during the 1910-19 period and almost as much as 
during the twenties. Then during the forties output increased 
almost as much as during the two previous decades. While 
the growth of output was smaller during the fifties than during 
the forties, the growth was greater than in any of the first 
three decades included in the tabulation and despite certain 
efforts to restrict production. 
The same kind of seeming discontinuity in output growth 
can be illustrated by changes in output in the Soviet Union. 
Between 1953 and 1958 the official index of gross agricultural 
output increased by 49% (!). This was an annual compound 
rate of growth slightly larger than 8%. Between 1958 and 
1962 gross output increased by approximately #9, or at a 
rate of less than 29, annually. While most Western observers 
did not expect the growth rate achieved between 1953 and 
1958 to be maintained, I do not believe that there was any 
one who predicted a growth rate as low as the actual one. 
Mr. ARCADIUS KAHAN and I predicted that output might in- 
crease by about 24% between 1058 and 1965 or at an annual 
rate of about 3%. Our projection should be compared with 
“he increase of 70% indicated by the Seven Year Plan. 
Ex post we can say a great deal, both for the United States 
and the Soviet Union, as to why there have been such changes 
in the rate of growth. But in making projections we are still 
not in a position to do very much in the way of predicting 
changes in methods of production or the effects of changes in 
incentives. For example, not all of the differences in views 
concerning the effects of the output price level on production 
in the Common Market or in the United States are due to self 
interest or political views: a large part of the differences exist 
(') I do not believe that the official output data for 1958 and 1953 are 
strictly comparable, but the relative overestimation of output in 1958 is 
not so great as to negate the point made in the text 
‘161 Johnson - pag. 36