DISTRIBUTION OF AGRICULTURAL INCOME 299 



30 bushels per acre, then the last 10 acres are worth 60 bushels 

 less than nothing to him because the addition of this new area 

 actually reduces his total crop. Now when land is so abundant 

 in a certain community, relatively to the number of farmers and 

 the quantities of labor and capital, as to allow 70 acres on the 

 average to every such farmer as the one assumed in the fore- 

 going illustration, or a proportional amount to other farmers 

 with different equipments, it is evident that land would com- 

 mand no rent at all, assuming that the land is all eqtially desir- 

 able. Even if he could get his land absolutely free of rent, it 

 would not pay any such farmer to cultivate as much as 70 acres. 

 The ref ore, if land were free, some of it would be allowed to lie 

 idle, and no owner would be able to rent his land for a price so 

 long as these conditions remained. 



The differential law of rent. If, however, the land were not 

 all equally desirable, and it never is all equally desirable in 

 any community, then the more desirable acres would com- 

 mand a price or a rental. So long as there remained any free 

 land anywhere in the community, the rent of any special piece 

 would normally represent the preference of the renter for it as 

 compared with land which he might have for nothing. The 

 poorer or more difficult of access this free land is* as compared 

 with the special piece in question, the higher the degree of 

 preference for the latter, and the higher its rent will rise. This 

 is one phase of the famous differential theory of rent which has 

 played so prominent a part in the economic discussions during 

 the last century. It is, beyond all question, a true theory, the 

 only question being whether it is so significant as many econo- 

 mists have supposed. 



Rent as determined by marginal productivity. Some are now 

 contending that the larger and more fundamental principle is 

 thai of the marginal productivity of land. For every farmer 

 the real and immediate problem is how much he can produce 



