Marginalism is a method of analysis used in microeconomics, which seeks to explain economic phenomena through mathematical functions (production, consumption, etc..). The term “marginal” was first used by Johann H. von Thünen in his “The Isolated State”, in 1826. The Marginal revolution, which took place a few decades later, around 1870, brought the prevailing classical view of value theory to an end. Indeed, thanks to the work of three economists: W. S. Jevons, Carl Menger and M.-E.-Léon Walras. Even though these economists worked independently, they shared a few ideas which made their work the beginning of the utility theory:
–utility was measurable in cardinal units, such as monetary units;
-the utility function is additive and separable;
-they all use the Gossen’ laws.