PRICE INCREMENT. 195 



major part of the wood, hence extremes in this respect must 

 be avoided. 



SECTION III. PRICE INCREMENT. 



Under price increment is understood the increment caused 

 by a change in the price of forest produce generally, inde- 

 pendent of the accompanying quality increment. It can be 

 positive, nil, or negative. 



Example. A hitherto inaccessible forest is brought into 

 communication with a large town by the construction of a 

 railway; the increase in the prices of the produce of the 

 forest represents the price increment, which in this case is 

 positive. 



Or, Owing to an increased import of forest produce the 

 price of the home production falls generally ; this represents a 

 fall of prices, in other words a negative price increment. 



Price increment depends partly on the forester and partly 

 on external causes, over which he has little or no control. 

 Of the former class of causes are, for instance, the construction 

 of good roads, development of industries which consume forest 

 produce, improvement in the general management leading to a 

 higher net value per unit of measurement. 



It is out of the question to construct a law showing the 

 changes in price. In some cases such changes affect all 

 classes of produce, in others only certain kinds. Under any 

 circumstances it is almost impossible to foresee them, except in 

 special definite cases. At the same time the price increment 

 is of considerable importance, as it affects the financial ripe- 

 ness of woods, and in this way influences the lines upon 

 which the management of the forest should proceed. 



The price increment is calculated in the same way as the 

 quality increment. If s represents the value of the unit of 

 measurement at the present time, and S the corresponding 

 value after n years, the price increment is = S s, and 



S = sxl'op 8 n 



