Economics Principles and Tools Author:Arthur O'Sullivan, Steven M. Sheffrin By emphasizing the five key principles, this book teaches readers how to think like economists by showing them how to use economic concepts in their everyday lives and careers. The authors make the material both accessible and motivating by using key concepts repeatedly, illustrating them with compelling real-world examples... more », and giving readers lots of practice at Active Learning; doing their own economic analysis. The focus on the five key principles of economics throughout the book includes: 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), and 5) The Reality Principle (distinguishing real from nominal magnitudes). Returning to these principles repeatedly explains the logic of economic reasoning and demystifies the tools of economics. For anyone who wants to see the relevance of economics in their life, career, and future.« less