“Profit and loss can be expressed in definite amounts of money. It is possible to ascertain in terms of money how much an individual has profited or lost. However, this is not a statement about this individual’s psychic profit or loss. It is a statement about a social phenomenon, about the individual’s contribution to the societal effort as it is appraised by the other members of society. It does not tell us anything about the individual’s increase or decrease in satisfaction or happiness. It merely reflects his fellow men’s evaluation of his contribution to social cooperation. This evaluation is ultimately determined by the efforts of every member of society to attain the highest possible psychic profit. It is the resultant of the composite effect of all these people’s subjective and personal value judgments as manifested in their conduct on the market.”

—Ludwig von Mises, Human Action