Carl Menger (/ˈmɛŋɡər/; German: [ˈmɛŋɐ]; 28 February 1840 – 26 February 1921) was an Austrian economist and the founder of the Austrian School of economics. Menger contributed to the development of the theory of marginalism (marginal utility), which rejected the cost-of-production theories of value, such as were developed by the classical economists such as Adam Smith and David Ricardo. As a departure from such, he would go on to call his resultant perspective, the "Subjective Theory of Value".