FARMERS* EABNINGS IN SOUTHEASTERN PENNSYLVANIA 23 
Table 20. — Average months of man-labor used on dairy farm*, according to the 
area in crops and the number of dairy cons l 
Number of cows 
Acreage in crops 
27.5 acres 
47.5 acres 67.5 acres 
87.5 acres 
6 
Months 
14.3 
15.7 
16.0 
Months Months 
19. 8 24. 1 
20. 7 25. 
Months 
10 
27.1 
]4 
21.5 
22.3 
22.9 
25.6 
26.1 
26.5 
28.0 
18 
29.0 
22 
29.8 
26 
23. 5 26. 9 
30.2 
1 The figures in this table are not simple averages, but are the smoothed averages or a " regression surface." 
This surface correlates with the actual labor on the individual farms to p=0.68. 
Table 20 shows the average labor used on dairy farms according 
to size in both cows and acres. A farmer who used only as much 
labor as that shown in the table for his size operation would be 
using just the average for the size of his business; one who used more 
would be using more than the average, and consequently would be 
making inefficient use of the labor unless he was able to get a suf- 
ficiently large extra product to offset the cost of the extra labor. 
Similarly a farmer who used less labor than average would be making 
more efficient use of his labor, unless the value of the product was 
cut down just as much as was the expense for labor. The difference 
between the labor used on each farm and the averages shown in 
Table 20 may be used, at least tentatively, as an index of efficiency 
in the use of labor. 
The relative importance of the efficiency with which the farm is 
operated, as compared with the size of the business, was determined 
by a statistical study of the dairy farms. This study showed that 
on the dairy farms the efficiency of operation was more than twice 
as important as the size of the business in determining operator's 
earnings. Differences in the efficiency of the dairy enterprise alone 
were responsible for two-fifths of the entire differences in earnings 
on the dairy farms, while differences in the efficiency of crop produc- 
tion, as measured by the crop index, were responsible for 7 per cent 
of the differences in operator's earnings. Thus efficiency in milk 
production was by far the most important factor in determining 
earnings on dairy farms. 
The index of labor efficiency was found to have practically no 
relation to the differences in earnings. This proves that the index 
was not a good measure of labor efficiency, since the farmers who 
used more than the average labor got enough more than the average 
product to pay for it. This means merely that in this region most 
farmers were making very efficient use of human labor, at least as 
between farms of the same size and with the same number of cows. 
The fact that on a farm of a given size twice as many cows wore 
handled with only slight increase in labor force is probably one 
reason why earnings increased so rapidly, as more cows were kept 
on a farm of a given size. 8 
8 The statements in this and the preceding paragraph are based on a multiple correlation of operator's 
earnings on the dairy farms with several factors, discussed in pages 57 to 59. 
