伯南克宏观经济学ch.pptVIP

Money in the Classical Model Monetary policy and the economy Money is neutral in both the short run and the long run in the classical model, because prices adjust rapidly to restore equilibrium Monetary nonneutrality If money is neutral, why does the data show that money is a leading, procyclical variable? Money in the Classical Model If money is neutral, why does the data show that money is a leading, procyclical variable? The classical answer: Reverse causation Changes in money growth precede changes in output doesnt mean that the money changes cause the output changes Reverse causation means money growth is higher because people expect higher output in the future; the higher money growth doesnt cause the higher future output If so, money can be procyclical and leading even though money is neutral The Misperceptions Theory and the Nonneutrality of Money Introduction to the misperceptions theory If producers misperceive the aggregate price level, then the relevant aggregate supply curve in the short run isnt vertical This happens because producers have imperfect information about the general price level As a result, they misinterpret changes in the general price level as changes in relative prices So the short-run aggregate supply curve isnt vertical But prices still adjust rapidly The misperceptions theory (10.4) In the short run, the aggregate supply (SRAS) curve slopes upward and intersects the long-run aggregate supply (LRAS) curve at P = Pe (Fig. 10.6) The Misperceptions Theory and the Nonneutrality of Money Figure 10.6 The aggregate supply curve in the misperceptions theory The Misperceptions Theory and the Nonneutrality of Money Monetary policy and the misperceptions theory Because of misperceptions, unanticipated monetary policy has real effects; but anticipated monetary policy has no real effects because there are no misperceptions Figure 10.7 An unanticipated increase in