This book originated from the translation of a book published in Italian: Keynes dopo Lucas. I fondamenti della macroeconomia, Rome, NIS, 1987. However, the present version is much more than a simple translation as I have added four new chapters (3, 5, 10 and 12) and I have revised all the others, adding sections, appendices, notes, and references. I have also tried whenever possible to improve the argument by rearranging and shortening the original text.

The preliminary plan for this monograph was conceived more than ten years ago, and I have worked on it continuously, though not exclusively, for all these years. In the meantime the original project has undergone a number of changes and ramifications, which constantly widened the gap between the text I was gradually building up and the goal I had set myself.

A few years ago I realized that the process was not converging towards the objective, and indeed could not converge without interrupting the evolution of my ideas. At that point I decided – so to speak – to ‘take a snapshot’ of the work at its present stage. In a few months I produced a very concise draft in which I set out certain essential points of my reflections on the foundations of macroeconomics, leaving further developments to be argued in articles.

The disadvantage of this selective procedure is that the treatment is summary and incomplete: the result can at best be considered as a ‘blueprint’, not as the building itself. The advantage, on the other hand, lies in the greater agility and accessibility of the argument. I have thus tried to keep the language as plain and comprehensible as possible.