- The document discusses the history and evolution of macroeconomic thought from Keynes' work in the 1930s establishing modern macroeconomics to recent developments. - It describes the neoclassical synthesis of the 1950s which integrated Keynesian and classical ideas and the influential IS-LM model. - In the 1970s, the rational expectations critique challenged Keynesian models and assumptions, leading to new classical, new Keynesian, and new growth theory work. - By the late 1980s, these schools of thought had integrated rational expectations and nominal rigidities into models still used today like New Keynesian and DSGE models.