Alfred Marshall

British economist whose Principles of Economics (1890) founded neoclassical microeconomics — introducing supply and demand curves, consumer surplus, elasticity, and partial equilibrium analysis.

The neoclassical synthesis: Marshall formalized the supply/demand diagram, developed the concept of price elasticity of demand, introduced consumer and producer surplus, and systematized partial equilibrium analysis. His methodological program ('natura non facit saltum') — gradual, rigorous, applied — contrasted with abstract theorizing and with Marxian political economy. Through his students (Pigou, Keynes) he shaped British economics for a generation. The Principles (8 editions, 1890-1920) was the dominant economics textbook for decades.