PRODUCTION IN RELATION TO CONSUMPTION 265 



since the herbage they produce can appear as human foodstuffs only 

 in the form of meat or milk. Granted that the production of animal 

 foodstuffs is a less economical way of utilising agricultural resources 

 in general for food production than is the cultivation of crops for 

 direct human consumption, it may nevertheless be true that these 

 regions are in practice capable of producing the maximum quantity 

 of foodstuffs only in the indirect form of animal produce. The 

 total area of land outside these regions devoted to permanent pas- 

 tures is, of course, very great, and depends not only upon the 

 demand for animal foodstuffs, but also upon the stage of agri- 

 cultural development ; but even if the demand for animal food- 

 stuffs were to fall to zero, some of the land in the above-named 

 regions might not be taken for crop cultivation, but might remain 

 as waste land so long as other more suitable agricultural land re- 

 mained within reach of the world's transport system. It is clear that 

 the existence of such areas, more or less removed from the prob- 

 ability of occupation for crop cultivation except of the fodder 

 type, favours the continued^ existence of animal industries in the 

 incidental form on some appreciable scale even under conditions of 

 quite limited agricultural resources. It is clear also that rotation 

 farming, in so far as it leads to the production of crops unsuitable 

 for direct human consumption, brings about the same result ; 

 however, if the demand for animal foodstuffs were to disappear, or 

 if agricultural resources became very limited, no doubt root and 

 fodder crops could and would be replaced by food crops to a con- 

 siderable extent. 



V. 



In a preceding chapter notice was taken of the tendency towards 

 substitution in consumption in the matter of foodstuffs and parti- 

 cularly of animal foodstuffs according to relative prices. It is now 

 to be observed that since the aim of such substitution is to replace 

 the more expensive article by a cheaper equivalent, its general 

 result, so far as market prices correspond to the real costs of pro- 

 duction, is to economise agricultural resources ; it often happens, 

 in fact, that the principle of incidental production in relation to 

 consumption can thus be taken fuller advantage of. In this con- 

 nection certain special forms of substitution in consumption may 

 now be examined in greater detail, with a view to noting their 

 effects upon the economics of production. The causes that underlie 

 changes in consumption contain a psychological as well as an 

 economic factor. We have seen already that habit and custom 

 give rise to marked friction to changes in this field ; so that these 

 are made not without difficulty in response to altered conditions 

 of purchasing power and of production ; but when once set on foot, 

 they often gather force and thus react themselves upon the. latter. 



The displacement of animal fats in consumption which is now 

 proceeding is a striking instance in point. The production of these 

 articles is a costly process in terms of agricultural resources, and is 



