212 ECONOMICS OF FORESTRY. 



wood, it would have produced an average per year 



of = 85 cubic feet; if a stand at 80 years 



contained 6880 cubic feet, it would have produced 



an average per year of — — = 86 cubic feet ; 



hence from the standpoint of volume production a 

 rotation of 80 years would be preferable. 



It will be readily admitted that value production 

 rather than volume production should be the aim, 

 and since with age the size and with it the value 

 increases, the year of maximum volume production 

 will be of interest only as denoting the lowest limit 

 of a rotation based on value accretion. If the 

 price of 80-year-old wood averaged for all sizes 



3 cents per cubic foot, and of 120-year-old wood 



4 cents, then in the above example the average value 



... ... 10200x4 



accretion in the one case would be = 



120 



$3.40 per year, while in the second case it would 



6880 X 3 . _ 



have been — ^ ^ = $2.58 per year, hence the 



80 



longer rotation would appear more favorable. 



But even the rotation of maximum value produc- 

 tion will not satisfy any private investor, since it 

 leaves out of consideration the expenditures nec- 

 essary to secure the result. The annual expendi- 

 tures for planting, taxes, administration, which are 

 necessary to secure the annual harvest, should at 

 least be deducted, and since these vary with the 



