Reviewers tell us that Case/Fair is one of the all-time bestselling principles of economics texts because they trust it to be clear, thorough and complete. This well-respected author team is joined for the 9 th edition by a new co-author, Sharon Oster. Sharonrs"s research and teaching experience brings new coverage of modern topics and an applied approach to economic theory, as demonstrated in the newEconomics in Practicefeature. Introduction to Economics; Concepts and Problems in Macroeconomics; The Core of Macroeconomic Theory; Further Macroeconomic Issues; The World Economy For those looking for a trusted and authoritative principles of macroeconomics text that focuses on international econmies as well as the Keynesian Cross. Case/Fair/Oster believe strongly, that a text should use the Keynesian Cross carefully and systematically, to build up to the AD/AS model. One of the great benefits of this approach, is that students of economics wonrs"t mistakenly apply what they learned about simple demand and supply to aggregate demand & supply. (A detailed summary of this approach can be found in the preface).