In order to comprehend the ontological construction below, please refer to the respective posts for all notions in italic.
A mutually interdependent existence of the commodities in the substitution effect sets them up as complements. Any economic good exist in conjunction with another; so they are dependent on each other. Taken even more specifically, commodities are complementary to each other as simple products. A productive consumption of every one of them is possible only in the context of other products, as they are created by the use of other goods and are realised in the existence of yet other goods. Quantitative variations of the complementary commodities happen in parallel fashion: a change in price should be effective for all complementary goods, determining their aggregate supply and demand unlike the substitutes.
Historical Backdrop
• AUGUSTIN COURNOT Researches into the Mathematical Principles of the Theory of Wealth: composite commodity.
• VILFREDO PARETO Manual of Political Economy: complementary goods.
• EUGEN SLUTSKY On the Theory of the Budget of the Consumer: complementary goods.
• JOHN HICKS and ROY ALLEN A Reconsideration of the Theory of Value: complementary goods.
• FRANCIS EDGEWORTH Papers Relating to Political Economy: complementary goods.
• KELVIN LANCASTER A New Approach to Consumer Theory: intrinsic total complements.