national production would have been increased had the cause. of the loss 
been eliminated. Estimates of value indicate the loss in dollars at 
the average prices received by farmers. The estimates of acreage 
equivalents represent the acreage that could have been saved if the loss 
had not occurred. 
The losses show in the tables are based on national annual averages 
chiefly for the 192={51 period. Because of wide variations in some 
kinds of losses from year to year, it was considered desirable, where 
possible, to use an average for the 10 years rather than a single year. 
In some instances, as pointed out later, lack of information on which 
to base estimates for the 10-year period made it necessary to use a 
shorter and more recent period. 
The manner in which estimates were computed can best be explained by 
the use of examples. Reductions in annual quantity of marketable crop 
production on farms may be considered first. In the case of insects 
and diseases attacking crops, estimates were made of percentage losses 
from potential production. Let us assume that the estimated loss from 
full production was 20 percent and that actual production was },00 million 
bushels, Total production with the cause of loss eliminated would have 
been 500 million bushels. The quantity loss is 100 million bushels 
(or 20 percent of 500 million bushels),-and is equivalent to 25 percent 
of the quantity actually harvested (00 million bushels). The loss in 
value of production was computed by applying the loss percentage in the 
same manner to the value of the crop. The acreage equivalent of the 
loss is 20 percent of the actual acreage, because had there been no loss 
the actual production could have been obtained on 20 percent fewer acres. 
Estimates of losses from deterioration in quality of crops produced on 
farms are included in the computation of losses in value and in the 
acreage equivalent of lost value described above. For example, if it 
were estimated that because of certain diseases affecting quality the 
total value of a crop was 20 percent lower than it would have been with- 
out this damage, the potential value of the crop would have been 25 
percent higher than it actually was. The acreage equivalent of the 
damage is 20 percent of the acreage used to produce the crop. This 
means that had there been no reduction in quality the actual value of 
this crop would have been produced on 20 percent fewer acres. 
Losses to crops while in storage on farms and to crops, including 
fruits and vegetables, in marketing channels also were measured in 
terms of quantity and value lost, and where possible in acreage equiva- 
lent of lost value, Farm quantities, values, and acreages are multi- 
plied directly by loss percentages to obtain the three measures of 
average annual losses. In the case of crops stored on farms the acreage 
to which loss percentages are applied is the equivalent acreage obtained 
by dividing the cuantity stored by average annual crop yields, The 
acreage to which loss percentages in marketing channels and processing 
are applied is that required to produce the quantities marketed or pro= 
cessed, assuming the same average yields as for the entire production. 
