5360S-9, 0-13-153606-0, O'Sullivan, Arthur, Principles of Microeconomics: Principles and Tools, 4/E//--> The book provides a clear, concise, and accessible presentation of key points. Its hallmark feature includes a focus on the 5 Key Principles of Economics-1) Opportunity Cost, 2) The Marginal Principle (comparing marginal benefits and marginal costs), 3) Diminishing Returns, 4) The Spillover Principle (for externalities in production and consumption), 5) The Reality Principle (distinguishing real from nominal magnitudes). For financial professionals and analysts.