Alfred Marshall (1842–1924) was a highly influential economist and a key founder of the neoclassical school of economics, whose work was driven by a desire to improve the material conditions of the working class. His book, Principles of Economics, first published in 1890, became the standard introductory textbook in the English-speaking world for half a century; its eighth edition was published in 1920 by MacMillan & Co. in London. A talented mathematician, Marshall advanced the study of supply and demand by using calculus to explain the functions of markets and firms. This work helped to formalize crucial economic concepts, including marginal cost, marginal utility, consumer surplus, and producer surplus. He is also noted for introducing the foundational model of supply and demand, often using the corn exchanges in English towns as a practical example. Marshall emphasized the importance of facts, and his observation that large firms could achieve lower unit production costs than smaller ones was central to his analysis. [1, 3] However, this particular insight was largely overlooked by subsequent neoclassical economists.