COKEELATIOlSr AS APPLIED TO FARM-SURVEY DATA. 



9 



"will show that, with the exception of the five between date of sale 

 and the other variables, they are all numerically equal to or above 

 .90. It has been shown that part, but not all, of the correlation be- 

 tween weight and price was due to the date of sale, and since date 

 of sale is only an approximate measure of age and length of feeding 

 period, it would not be reasonable to expect the net correlation be- 

 tween it and the other variables to be perfect. The fact that all the 

 net coefficients except these five are so nearly -\-l or — 1, when 

 there was every reason to expect perfect correlation, is striking 

 proof of the reliability of this method of analysis as well as of the 

 accuracy of data such as those under consideration, and is at the 

 same time a very good check on the computations. 



In the interpretation of the coefficients care must be taken to dis- 

 tinguish between subjective and relative factors, i. e., between cause 

 and effect. Most interest is naturally attached to determining to 

 just what extent each of the factors under consideration is respon- 

 sible for the farmer's loss or gain in his baby-beef enterprise, and 

 iiere there can be no confusion of cause and effect, for all the other 

 factors are necessarily causative. Throughout the remainder of the 

 investigation the amount of profit or loss is an effect and not a cause, 

 and consequently too much weight should not be given to a coefficient 

 in which the effect of profit has been taken into account. 



THE APPARENT COERELATIONS. 



In taking up the discussion of the coefficients themselves, the ap- 

 parent correlations between profit and the other five factors are 



first considered : 



Coefficients of correlation. 



Profit 

 and 



Weight. 



Profit 

 and 

 Value 

 per hun- 

 dredweight. 



Profit 



and 



Value 



of feed,' 



Profit 



and 



Cost at 



weaning 



time. 



Profit 



and 



Date of 



sale. 



+.28 



+.23 



-.27 



-.73 



+.14 



These five coefficients should show the average effect of each of the 

 five factors on the profit. The coefficient for profit and date of sale 

 (+.14i) shows that the profit on the calves sold early in the season was 

 practically as great as on those sold later. The first three are all of 

 nearly the same size, but are too small to indicate more than slight 

 relationship. In regard to them we may say, therefore, that in the 

 data under consideration: (1) There was a tendency for the heavier 

 calves to return a greater profit; (2) there is some correlation be- 

 tween price per pound and profit; (3) generally speaking, the farmer 

 whose calves consumed feed worth more than the average made a 

 profit somewhat less than the average. 



