602 



READINGS IN RURAL ECONOMICS 



The chart on page 603 shows the labor incomes made by farm- 

 ers whose crop yields were 1 5 per cent or more below the average 

 and by those whose crop yields were 15 per cent or more above 

 the average. Each cross represents one farmer and its position 

 indicates his labor income. 



The relative positions of the two entire groups show the im- 

 portance of crop yields. In each group there are great varia- 

 tions due to size of farms, receipts per cow, and many other 

 factors. There is only a little correlation between crop yields 

 and receipts per cow or size of farm (p. 503), so that these in- 

 fluences scatter the farms in each group but do not affect the 

 position of the group as a whole. The scattering within the 

 group misleads many persons who are used to drawing conclusions 

 from individual cases. There are plenty of individuals who are 

 doing better with poor crops than some one else is doing with 

 good crops. Such cases are because of some other difference 

 that is great enough to more than offset the result that comes 

 from the crop yields. 



Good crops are one of the primary factors affecting profits, 

 but phenomenal crops are not necessary. Few farmers raise 

 crops more than a third better than the average. Good crops 



must be charged to a percentage basis. The method of figuring the percentage 

 yield is illustrated as follows : Suppose that a farmer has 20 acres of wheat yield- 

 ing 15 bushels, 30 acres of oats yielding 40 bushels, and 50 acres of hay yielding 

 1.7 tons. Each of these yields is compared with the average of the region as 

 given on page 626. The wheat yield is 81 per cent of the average. The oat yield 

 is 97 per cent. We then have 



Per Cent 



Percentage 

 TIMES Acres 



35 



5 



105 



81 

 97 



1,620 



3.395 

 6,000 



11,015 



Dividing 11,015 by 105, we find that this farmer's yields are 105 per cent. This 

 we call the crop index. 



When the total crop is given, a short way of figuring crop index is to divide 

 the total yield of each crop by the average for that crop, add the results, and 

 <}ivide by the number of acres. It will be seen that this is the same as the above 

 method except for the order in which the operations are done. 



