outlines how macroeconomics has evolved from its birth in the 1930s as a theory separate from microeconomics, resulting in a split between macro- and micro-theories, and ended up with a new hegemonic paradigm based on microfoundations. The ensuing policy thinking witnessed a transformation from "active" macro-policy after the Great Depression to a far more "passive" macro-policy during the last quarter of the twentieth century, which may have contributed to missing the signs of the impending Long Recession of 2008. ¿When the 2008 crisis struck, macroeconomists were caught with models that were theoretically elegant yet inappropriate to the needs of the moment. A broader historical perspective may have prevented the jettisoning of Keynesian models that had proved useful in the past and might have done so again. This highly readable book by Arie Arnon is a wonderful antidote to economists¿ short time horizon and contributes mightily to restore the profession¿s ¿collective memory¿ of the diversity of ideas within macroeconomics.¿Professor Dani Rodrik, Harvard Kennedy School