【正确答案】 A

【答案解析】If the effects of an increase in the growth rate in the supply of money are anticipated, then prices, wages and interest rates will rise quickly in response to an increase in the money supply. However, if the increase in the money supply catches the economy by surprise, then there will be a temporary but real increase in output and drop in unemployment since decision makers will at first think the increase in the money supply is an increase in demand. If the effects of an increase in the money supply are unanticipated, the real rate of interest will fall in the short run, stimulating an increase in demand. This in turn increases output and employment. The long-run effect is higher prices and nominal interest rates. Expectations often determine whether economic policies succeed in achieving their objectives. The effects of fiscal or monetary policy shifts can be dramatically different, depending on whether the shifts were expected or not.