This book has critically reviewed various theories of money and inflation with special focus on the classical quantity theory of money and Keynes. It also compares numerous empirical studies over the globe to the two of the big competing inflation theories and tried to show which is really explaining the modern economy. A lot of effort has been exerted to keep the quality of the book and it also involves various sophisticated econometric applications to support the findings more reliable. The book has passed various review process and has been acknowledged for its high quality including the international journals. Despite the critical reviews made to it, the book has been being edited and restructured by many doctors in economics, and the work has acknowledged for being the best of the year in the university.