So far as variations in the objective exchange-value of money are foreseen, they influence the terms of credit transactions. If a future fall in the purchasing power of the monetary unit has to be reckoned with, lenders must be prepared for the fact that the sum of money which a debtor repays at the conclusion of the transaction will have a smaller purchasing power than the sum originally lent. Lenders, in fact, would do better not to lend at all, but to buy other goods with their money. The contrary is true for debtors. If they buy commodities with the money they have borrowed and sell them again after a time, they will retain a surplus over and above the sum that they have to pay back. The credit transaction results in a gain for them. Consequently it is not difficult to understand that, so long as continued depreciation is to be reckoned with, those who lend money demand higher rates of interest and those who borrow money are willing to pay the higher rates. If, on the other hand, it is expected that the value of money will increase, then the rate of interest will be lower than it would otherwise have been.
Ludwig von Mises, The Theory of Money and Credit
capitalism, economics, freedom, money