Part I: Evolution of Variable Quality in Economic Thought; Chapter 1: Introduction; Chapter 2: Early Attempts to Introduce Variable Quality; Chapter 3: Theory of the Consumer and Variable Quality; Chapter 4: Theory of the Consumer and Variable Quality; Chapter 5: Quantity-Quality Trade-Offs; Chapter 6: Wants, Characteristics, Price Indices, and Variable Quality; Part I: A New Economic Theory of the Consumer; Chapter 7: Interpretations of the Houthakker Constraint; Chapter 8: Consumer Surplus, Willingness-to-Pay, Perception, and b i; Chapter 9: Stability of b i , Attractors, and Self-Perception; Chapter 10: Willingness-to-Pay, Targeting, Learning, and Demand Prices; Chapter 11: ConsumerProducer Interaction and the Market; Chapter 12: Transaction Regions, Neighborhoods, and Targeting; Chapter 13: Individual Consumer Demand from QualityQuantity Space; Chapter 14: Individual Consumer Demand from x i x j Space; Chapter 15: Individual Consumer Demand from x i x j Space