24 BULLETIN" 1277, U. S. DEPARTMENT OF AGRICULTURE 
Table 23. — Net labor input per bushel of wheat for labor applied in different 
operations 
Operation 
Labor input per addi- 
tional bushel of yield 
Harrowing before seeding . 
Harrowing after seeding.. 
Disking 
Man hours 
0.67 
0.64 
L12 
Horse hours 
2.81 
2.62 
4.72 
One weakness of the foregoing method of analysis is the fact that 
the various inputs do not vary independently of each other. For 
example, large doses of fertilizer mean more man labor, horse labor, 
and expense at the time of harvest. More feed means more man 
labor. More equipment may mean more or less man labor. Hence, 
in further development of the statistical technique such relations 
should be kept in mind. Possibly the results from associated inputs, 
as well as from individual inputs, might be determined. 
APPLICATIONS 
The first part of this bulletin has presented the method of an- 
alyzing input variations so as to get them in form sufficiently accu- 
rate and tangible for use. This part will discuss the applications 
previously outlined. 
THE LEAST-COST COMBINATION OF INPUTS 
One important practical need for production data is to enable 
any farmer to forecast the particular combination of land, labor, 
capital, feed, livestock, etc., which will make it possible for him to 
produce at least cost per unit of product. Attempts have been made 
to determine this on the basis of average inputs, but obviously the 
results are likely to be misleading. Not until the individual is able 
to estimate for his farm with a fair degree of accuracy how output 
will vary year in and year out with variations in input, and how 
one input will vary with another, can he forecast a reliable least- 
cost combination. Consequently, methods of the kind developed in 
the preceding pages are absolutely necessary for any useful least- 
cost determination. 
Given the variations in input per unit of output for all the cost 
elements as input changes, all that is necessary to determine that 
combination which produces at least cost per unit is to apply pre- 
vailing cost rates to the inputs in the various combinations and 
locate the least-cost combination. 
There will be definite limitations in many cases. For example, one 
man may be limited by labor, another by capital, another by feed 
available, and another by acreage. There will probably be a different 
least-cost combination with each different limitation or combination 
of limitations. 
The method of presenting the data for general use in this way 
is to construct tables of input variations, such as Tables 17 to 21, 
and to follow these with tables of costs under various assumptions to 
serve as guides to farmers in working out their own least-cost combi- 
nations. The beef-production analysis will here be used to illustrate 
the method of presentation. 
