The Handbook guides the reader through the major features of Economy-wide Microeconomics, starting with a detailed description of the classic Arrow - Debreu model of the economy and concluding with a discussion of research aimed at relaxing various Arrow - Debreu conditions. Exercises are placed throughout the Handbook, with references to places in the literature where complete solutions to them may be found. Contents - Volume 1: Existence and Uniqueness of Equilibrium / Volume 2: Stability and Optimality of Equilibrium / Volume 3: Comparative Statics and Applications / Volume 4: Tests and Extensions.