In order to comprehend the ontological construction below, please refer to the respective posts for all notions in italic.
Change in the price of a commodity has substituting consequences, as other commodities are entangled with it. With a rising price of goods, other goods replace them in the realm of consumption; besides, with a falling price of goods, they themselves are consumed more extensively. On the market, every commodity is priced in other commodities, there for the demand and the supply for any are dependent on the availability of all commodities taken together. Transitory change in the proportion of one of them affects the proportion of the rest; in result, a new alteration of the interdependent proportions is enacted. Thus commodities are further defined as complements or substitutes to each other.
Historical Backdrop
• ALFRED MARSHALL Principles of Economics: principle of substitution.
• JOHN HICKS Value and Capital: substitution effect.
• EUGEN SLUTSKY On the Theory of the Budget of the Consumer: laws of demand.