The authors have worked hard to ensure that the Third Edition of Principles of Economics is the best edition ever. This edition features the following improvements.

• A new core principle has been added to Chapter 1 that says “A person [or a firm or a society] is more likely to take an action if its benefit rises, and less likely to take it if its cost rises. In short, incentives matter.” Also the discussion of positive vs. normative economics has been expanded.
• The supplements package has been extensively revised and improved. We have new authors for the micro Test Bank, the micro Study Guide, and the macro portion of the Instructors' Manual. This material has also been extensively checked for accuracy. These improvements should help in the difficult tasks of learning and of teaching Principles of Economics.
• The international trade chapter [now Chapter 9] has been made more robust and moved forward. Because international trade involves important micro principles and policy issues, students will benefit greatly from this expanded coverage early in the book.
• The strategy chapter [now Chapter 11] has been revised to include more on oligopoly and monopolistic competition--two topics that are typically used to present game theory.
• Indifference curve material has been added as an appendix to Chapter 5. In the Second Edition this material was placed on the web site; in this edition, it is a part of the text, making it easier for students to access it.
• DiscoverEcon with Solman Videos: We now have an interactive software program for homework management, tutorials, videos, and assessment. This software houses both the best-selling tutorial software for Principles of Economics, and brand-new videos featuring Paul Solman of the NewsHour with Jim Lehrer on PBS. This product includes 250 minutes of video that explains introductory economic concepts in a real-world, student-friendly manner. DiscoverEcon includes updated graphing applets, interactive exercises, animated tutorials, and hundreds of multiple-choice questions to test student comprehension in each book chapter. The videos are integrated into the website and are available web streaming or on DVD.