FARMERS' EARNINGS IX SOUTHEASTERN PENNSYLVANIA 59 
The result obtained for the labor index in this case confirms the 
earlier conclusion that labor is in general used with very uniform 
efficiency throughout the area. Differences in the efficiency with 
which labor is used on the dairy farms alone are only one-third as 
important in their effect on operators' earnings as were variations in 
labor efficiency on all farms thrown together. This indicates that 
although labor in general is used with very uniform efficiency on the 
dairy farms, it is not used quite so efficiently on the crop, small 
dairy, or other special types (excluding mushroom farms), and that 
there is more room for improvement in the utilization of labor on 
these other farms. This is but natural, since the dairy farms come 
closer to providing year-round full-time employment in profitable 
work than do any of the other types except the mushroom iarms. 
Further study was made of the " net " relation between the number 
of cows, acres in pasture and in crops, and operators' earnings, to 
see if there was any indication of the "best" combination of these 
factors after eliminating the other disturbing elements. Although 
there was some very slight indication that farms of 100 acres or 
more returned the largest earnings when abouc one-third of their 
area was in pasture, the observations for smaller farms were con- 
flicting, and curvilinear correlations showed that the proportion 
between pasture and crop land had no perceptible influence upon 
earnings. Study of the relations between number of cows and acres 
gave similar negative conclusions. These results indicate that in 
an area of as varied topography as Chester County it is not possible 
to lay down definite standards for farm organization from the results 
of statistical studies of this type, but that instead each farm must 
be treated as a separate unit and the most profitable organization 
for it worked out by direct study of its own resources and possi- 
bilities along the lines suggested in various publications of the United 
States Department of Agriculture and other agencies (3, 10). 
RELATION OF FEEDING PRACTICES TO EFFICIENCY OF MILK PRODUCTION 
The tabular study in the section devoted to causes of variations 
in the efficiency of milk production demonstrated that the "dairy 
index"' was the resultant of two groups of forces — those determining 
the price at which the milk sold and those determining the efficiency 
with which it was produced. And as further shown there, the produc- 
tion per cow was one of the most important factors determining the 
feed cost of milk production. 
The following statistical study was made to measure the impor- 
tance of the different factors affecting milk production under farm 
conditions as far as it could be done from the data available, and to 
demonstrate the importance of good dairy husbandry directly from 
the farm records themselves. 
Following the methods previously worked out for studying the 
efficiency of enterprise operation, the analysis would include three 
stages : 
(1) Determination by statistical means of the relation be- 
tween input and output. 
(2) Application of prevailing costs and prices to the inputs 
at various combinations of input factors to determine the least 
cost or greatest profit combination under prevailing conditions. 
