Diminishing Marginal Utility
Diminishing Returns
In economics, utility is the satisfaction or benefit derived by consuming a product, thus the marginal utility of a good or service is the change in the utility from an increase in the consumption of that good or service. A 'diminishing utility' is simply the ongoing decrease in utility from additional goods or services.
Origin
German economist Hermann Heinrich Gossen first formulated the principle in 1854 in his book The Laws of Human Relations, now known as "Gossen's First Law." The concept had earlier roots in Daniel Bernoulli's 1738 work on risk measurement. The Marginal Revolution of the 1870s brought the principle to prominence through William Stanley Jevons (1871), Carl Menger (1871), and Léon Walras (1874), who integrated marginal utility into mainstream economic theory.