POULTRY PROFITS 



89 



Table 17. Multiple Correlation Coefficients and Probable Errors of 



Estimates 



Coeft'ic'ients 



Multiple Correlation R=^ 

 Probable Error of Ustiniate 

 for Labor Return 



Per Flock 

 1927 



.904. ± .Oil 



$4-73 



Per Initial Bird 

 1927 1926 



.820 ± .019 .797 ± .020 



$0.78 



$0.7() 



The Importance of the Individual Factors 



Tin- relative importance of tiie several factors in the two analyses which 

 took labor return per bird as the dependent factor were as follows: 



A. Index of Chanjie in Flock Size 



B. Annual Egg Production per Bird 



C. Price of E.s>gs 



D. Fall Egjr Production 



E. Other Credits than Market Eg.us 



Total 



Per Cent Determinat'on 



1926 1927 



14.0 10.4 



26.7 22.1 



0.5 2.5 



0.1 — 0.5 



22.2 32. « 



Combined Importance of A, B, C, D, and E 63.5 



Residual \'ariation 36.5 



100.0 



67.1 



32.9 



100.0 



This indicates that the most important factors affecting labor return 

 per bird are annual egg production per bird and other credits than market 

 eggs. Next comes index of change in flock size. The price of eggs and 

 the fall egg production are really more important than these coefficients 

 indicate, because of intercorrelation with annual egg jiroduction. 



Further light on the price of eggs' is furnished by a study of the rela- 

 tive variability of the factors considered. The coefficients of variability 

 (computed by expressing the standard deviations as percentages of the 

 re-;pecti\e means) were as follows in the two years: 



Factor 



Index of change in flock size 



Annual egg production 



Price of eggs 



Fall egg production 



Other credits than market eggs 



Coefficients of Variability 



This means that the variability (or diff'erence from farm to farm) in 

 the price of eggs was considerably less than the variability in the other 

 factors studied. Hence the variability in labor return due to diff'erences 

 in price received for eggs is less than the variability due to the other 

 factors. 



To measure the relative influence on egg receipts of diff'erences in egg 

 production and in price received for eggs, a simple correlation calculated 

 between egg receipts and egg production for 1927 gave r=: .82 and 

 r-= 67 per cent. Therefore, since egg production and average price al- 

 mcst completely determine receipts from eggs, variations in egg produc- 

 tion were about twice as imi^ortant as variations in price in aff'ecting egg 

 receipts in 1927. 



•Approximately two-thirds of the variation in labor return per bird can 

 be explained iri terms of four of the factors studied. The remaining 

 variation is due to factors not included in the study, probably for the 

 most part diff'erences in feed consumption and cost factors. The discus- 



