200 THE KEGULAT10N OF NUMBERS 



which an industry is absolutely dependent, is strictly limited, 

 after a time equal increments of capital and labour will not 

 produce equal returns. In other words the returns to the same 

 doses of capital and labour will diminish. This, however, will 

 only occur when, as stated above, the supply of some agent in 

 production is restricted ; otherwise when an industry enlarges 

 there will, as a rule, be an increasing return. The more labour, 

 apart from diminishing returns, the better. 



When speaking of agriculture it was said that diminishing 

 returns only supervene when there are no improvements in the 

 arts of agriculture. This is true in general of all other industries. 

 Any increase in the arts of production will in general admit of 

 more labour and capital being profitably employed ; if there are 

 no further improvements, there will after a time come a point 

 when diminishing returns will again supervene. The following 

 out of the working of these laws in detail would call for a long and 

 intricate discussion. Since the problem of quantity is only 

 touched upon in its broadest outlines, such a discussion is not 

 necessary here. The broad fact which emerges, and which alone 

 is relevant here, is that, since the laws in general are applicable 

 to all industry, there will be, taking into account on the one 

 hand the known arts of production and on the other hand the 

 habits and so on of any people at any one time in any given area, 

 a certain density of population which will be the most desirable 

 from the point of view of return per head of population. There 

 will, in fact, under any given circumstances always be an optimum 

 number ; if the population fails to reach that number or if it 

 exceeds it, the return per head will not be so large as it would 

 be if it attained that number. This conception is of such impor- 

 tance that its formulation in other words by a modern economist 

 may be quoted. ' At any given time, or, which comes to the 

 same thing, knowledge and circumstances remaining the same, 

 there is what may be called a point of maximum return, when the 

 amount of labour is such that both an increase and a decrease in 

 it would diminish proportionate returns. ... If we suppose all 

 the difficulties about the measurements of the returns to all 

 industries taken together to be somehow overcome, we can see 

 that at any given time, or knowledge and circumstances remain- 

 ing the same, just as there is a point of maximum return in each 

 industry, so there must be in all industries taken together. If 



