Though apparently siblings from the same family, New Keynesianism and Post-Keynesianism are completely different schools of economic thought. As to why and in what regard exactly, that is what this book is all about. While the former is the official label of the current mainstream in economic research and teaching (rather than neoclassic economics, which would be more apt a term), the latter tries to preserve the original thinking of John Maynard Keynes, but also additional ideas and concepts of all those building on his work.