is constantly changing with conditions.  The current new supplies of gold are comparatively regular.  For centuries at a time there was little change in the methods of mining gold and there were no radical changes in its output.  The nature of the use of gold, likewise, is such as to made changes in the amount of it needed, under ordinary conditions, more stable than is that of most other goods.  Moreover, the stock of gold in monetary uses is but slowly worn out; it is, therefore, a large reservoir into which flows a comparatively small stream of annual production; the existing stock is twenty or thirty times the annual output.  Yet the value of gold expressed in other things is never quite stable, and sometimes several influences combine to affect it greatly and suddenly.  Recent inventions, chemical and mechanical, moreover, have considerably altered the conditions of production.  While, therefore, it is the best standard yet devised and put into actual practice, it is very imperfect.  A standard better than a single metal, more stable than a single commodity, is desirable if it can be found.

Sec. 14. #Various ideal standards suggested.# It may, perhaps, be agreed that the ideal standard of deferred payments is one that would insure justice between borrower and lender.  Yet different views may be and have been taken as to what constitutes justice in this matter.  The suggestion is attractive that repayment should involve the return of enjoyment equal to that which could be purchased with the sum at the time of the loan.  Such a standard is impossible of perfect realization in any general way, for men’s circumstances are constantly changing.  To insure even to the average man the same amount of enjoyment is only roughly possible.  The same goods do not afford the same enjoyment when conditions, either subjective or objective, have changed.  Another suggestion is that the goods returned should represent the same sacrifice as those loaned.  Here again the difficulty is in the lack of a standard applicable to all men.  Whose sacrifice?  That of the lender, who may be rich, or that of the borrower, who may be poor?  Some have supposed that the condition of equal sacrifices was met by the labor standard, according to which the sum returned should purchase the same number of days of labor as when borrowed.  But what kind of labor is to be taken, that of the lender or that of the borrower or that of some one else?  Labor is of many different qualities, which can be exactly compared only through their objective value in terms of some one good.[20]

It must be recognized that any possible concrete standard of deferred payments will sometimes work hardship in individual cases.  The best average results for justice and social welfare will be secured by measuring debts in some standard that will change least often, and least rapidly, in relation to the great majority of people of all classes in the community.