DISTRIBUTION OF WEALTH 



measured by the amount of surplus over costs 

 which can be produced upon a given grade of land. 

 But this is not true. The farmers who are quali- 

 tatively more efficient find greater opportunity for 

 the employment of their superior skill and knowl- 

 edge upon the more productive, than upon the 

 less productive land. The farmers who possess 

 a relatively high degree of qualitative efficiency 

 can win a larger return from land of any grade 

 than can their less efficient competitors, but this 

 extra product due to superior ability is greater 

 on the more productive than on the less productive 

 land and for this reason the more efficient farm- 

 ers compete only for the more productive land, 

 and are willing to pay more for it than the less 

 efficient farmers can afford to pay. The qualita- 

 tively less efficient farmers go on competing for 

 the less productive land until marginal farmers are 

 shifted to marginal land. Hence, the difference 

 between the rent of marginal land and that of the 

 more productive land cannot be measured in terms 

 of differences in the amount of the surplus which 

 would exist if land were the only factor which 

 varies in productivity. 



This can be illustrated by means of a diagram. 

 In Fig. 6 the land is represented as varying in 

 productivity from left to right, the most produc- 

 tive land being at the left, and called A grade 

 land; the least productive being at the right and 

 called B grade land. (For the sake of simplicity, 

 165 



