This work proposes a new approach to macroeconomics which draws upon the experience of the Japanese economy. The approach is similar to the Old Keynesian view: it rejects the Walrasian approach, and singles out real demand as the fundamental determinant of output in the economy as a whole. However, by maintaining that real demand constraints are important not only in the short-run, but in the long-run as well, it goes beyond what is normally understood as the Keynesian approach. It is also very different from the New Keynesian Economics; in particular, it regards the rigidity of nominal wages/prices as of secondary importance. The work is extensively illustrated by almost 200 figures and tables of data.