Foundations Of Economic Analysis by Paul Samuelson

A rigorous reworking of economic theory that treats behavior as constrained optimization within equilibrium systems, using mathematical tools to derive comparative statics and stability results. It unifies consumer, firm, and macro relationships through maximization under constraints and Lagrange methods, articulates the correspondence principle linking stability to qualitative predictions, and employs analogies such as Le Chatelier effects. The result is a general framework that underpins modern demand, welfare, and policy analysis.