EXPECTATION VALUE. 145 



By introducing the value of ^S'^ — 



the above formula becomes 



10p'"('y,+T„x10p'--"+ . . . +TqXl-Op^-'' + 



^^ iop^-1 ^- 



If )n is smaller than a, that is to say, if the age of the wood 

 is less than the year, when the first thinning occurs, then the 

 above two formubie become respectively — 



l-0^>'-'" 

 and 



.nj, ^ I'Op- (F,+ r„Xl-Oy-"+ . ■ . -^T.Xl-Of-'-c) _ 

 1-0^/ - 1 



If m = 0, and cultivation has not yet taken place — 



i;+ T„ X i-op'- -"+...+ 1; X i-op'' - '-c x vojf 



oj^ -E (l-0;/-l)+'-6', 



= — ^^ — ' ,, , — = S. = the soil expectation value. 

 l"Oj>' 



(2.) The forest expectation value can also be calculated 

 direct out of the expected receipts and expenses, in which 

 case — 





l-Oi?'- - 1 "^ l-Op'- - 1 ^ • • • "^ i-oy _ 1 



