Keeping a book on macroeconomics up to date is a challenging and neverending task. The field is continually evolving, as new events and research lead to doubts about old views and the emergence of new ideas, models, and tests. The result is that each edition of this book is very different from the one before. This is truer of this revision than any previous one.

Advanced macroeconomics 4th ed. (2011), "Preface to the Fourth Edition"