In the Keynesian model we thought of monetary policy as exogenous in the sense that the money supply, Mt, was set exogenously. This is useful for understanding the model but doesn’t really describe how monetary policy works in practice. In the real world, central banks adjust the money supply (and hence interest rates) endogenously in response to changing conditions. In this set of notes we dis...

thank David Weil, on whose notes substantial parts of the chapters on Money and Prices and Investment are based. Kyung Mook Lim and Wataru Miyanaga provided detailed corrections to typographical errors. Several classes of Brown students have provided suggestions and corrections. All remaining errors are mine.