232 PRINCIPLES OF RURAL ECONOMICS 



are special circumstances under which share rent may prove 

 more satisfactory. Both methods call, in about equal degree, 

 for carefully drawn contracts and mutual good will. Under the 

 cash-rent system, the tenant is more likely to exploit the soil 

 and leave it depleted. Under the share-rent system the tenant 

 is less assiduous in cultivating the soil, especially the poorer 

 parts, the fence corners, or the other parts where the advan- 

 tage of cultivation is more or less doubtful. In general, it may 

 be said that cash tenancy leads to more thorough farming, but 

 endangers the future fertility of the soil. 



There is a fundamental economic reason, aside from the gen- 

 eral superiority of cash over share tenants, for the observed fact 

 that cash tenancy leads to more thorough cultivation of the soil 

 than share tenancy. The cash tenant gets all the advantage of 

 his own superior cultivation, whereas the share tenant gets only 

 a share of that advantage. That is to say, after the cash tenant 

 has produced enough to pay his rent, every additional dollar 

 which he can make the farm produce goes into his own pocket, 

 whereas, no matter how much the share tenant adds to the prod- 

 uct, he gets only a share of the increase. Under the principle 

 of diminishing returns the cash tenant can afford to increase the 

 intensity of his cultivation up to the point where the additional 

 cost approximates in amount the additional product, whereas the 

 share tenant could only afford to carry the cultivation up to the 

 point where the additional cost would equal in amount his share 

 of the additional product. This principle may be illustrated by 

 means of the diagram on the following page. 



Let the amount of labor to be expended in the cultivation of 

 the farm be measured along the line OX, and the cost along 

 the line OY, the cost per unit being represented by the distance 

 OA. Also let the curve YHKBX represent the product to be 

 secured by successive applications of labor to the cultivation of 

 the soil. The cash tenant will pay a fixed sum for the farm, 



