PROPOSITIONS CONCERNING CONSUMPTION The economic order of consumption is modified by changes in the relative cost of producing dif ferent commodities. It has been pointed out in the preceding chapter that commodities are chosen not in the order of their positive utility, but in the order of their surplus of utility over cost. Any modifications in the productive processes, therefore, which affect the costs of producing certain commodities more than the cost of producing others, since they affect the surplus of utility, must modify the economic order. This modification is inde pendent of any changes in the positive utility of the commodities. The construction of a railroad will cheapen the production of a mul titude of commodities, but will affect those produced at greater distances more than those produced near at hand. If it affected all alike, it could not modify consumption. It does not 93 increase the utility of the commodities pro duced at a distance, but it increases their relative surplus by lowering their relative cost. If for any reason costs are increased, but not uniformly, a similar modification takes place. Taxation never affects the cost of all com modities alike. It therefore influences con sumption, leaving the surplus larger on certain commodities than on others. The immediate effect of such modifications may be an increase or a decrease in the variety of consumption. A cold climate adds to the cost of producing all kinds of food which are to be met with in tropi cal climates. But it increases the cost of securing fruit more than that of producing meat. In the warm climate there is a much greater surplus in fruit than in meat. The colder climate diminishes the surplus in each case by increasing the cost, but diminishes the meat surplus less than it does the fruit surplus. Under these circumstances it will be easier to increase the variety of consumption, since there will be almost or quite as much inducement to produce the one as the 1 Patten, Consumption of Wealth, p. 47.
The economic order of consumption is modifed by changes in appetites. Progress from primi tive to advanced stages involves a decrease in the intensity of the appetite for food, and par ticularly for the few varieties of food and drink which are so eagerly desired by human beings on a low plane of civilization. The first reason for the greater intensity of appetite under primitive condition is the irregularity of the food supply. The appetite must be stronger,
the capacity for food greater, when periods of scarcity succeed those of plenty. When food is regularly supplied, the need for the more intense appetite disappears. The few articles of which the diet of primitive man is composed contain necessarily all the food elements essen tial to the system ; but while rich in some of these elements, they are poor in others. An increase of variety, if it adds to the diet articles which contain larger proportions of those ele ments which are present in the earlier articles only in small quantities, will result in a further decrease of appetite. If one eats only meat, it is necessary to consume larger quantities in order to get a sufficient amount of starch and other elements demanded by the system ; but if corn and potatoes are added to the diet, the needs of the system for these particular ele ments are much more quickly supplied, fewer pounds of food need to be taken when the diet is thus varied, and the appetite is correspond ingly reduced.
Improvements in shelter and in clothing lessen materially the demand of the system for food, as a source of animal heat, the effect of which may be seen in the decrease of appetite ; and finally the tendency is still further strengthened by the introduction of machinery and mechanical devices which re lieve the system of the muscular strain in volved in heavy manual A reduction of appetite for food has followed each of these changes, but it has shown itself much more with some commodities than with others. A measure of disgust becomes associated with the thought of eating the very kinds of food 1 Professor Marshall speaks of the effects of machinery in relieving that " excessive muscular strain which a few genera tions ago was the common lot of more than half the working men even in such a country as England." that once gave, and if the older conditions were restored would again give, the keenest pleasure. These changes in appetite modify the economic order of consumption by act ing riot on the cost, but on the utility. Cost may remain the same, but surplus utility is reduced because total utility is reduced. Since the utility is not reduced on other commodi ties as it is on food, and since it is not uni formly reduced on all kinds of food, the order in which commodities are desired is changed. The economic order of consumption is therefore modified by any changes in appetite.