For Principles of Microeconomics courses. For a complete multimedia book tour of Economics: Principles, Applications, & Tools, 8e Click Here. For a look at the Supply & Demand Chapter of this title, Click Here. Questions that drive interest, applications that illustrate concepts, and the tools to test and solidify comprehension. Students come into their first Economics course thinking they will gain a better understanding of the economy around them. Unfortunately, they often leave with many unanswered questions. To ensure students actively internalize economics, O'Sullivan/Sheffrin/Perez use chapter-opening questions to spark interest on important economic concepts, applications that vividly illustrate those concepts, and chapter-ending tools that test and solidify understanding.