实行固定汇率制的中央银行可能会牺牲其制定国内货币政策的自主权。有一种说法认为，如果以上情况属实的话，那

么中央银行也就放弃了它运用货币政策来控制工资一价格螺旋式上升的能力。这种说法通常这样表述：“假设工人要求更高的工资而雇主同意的话。那么雇主就会提高其产品价格以弥补更高的工资成本。因为价格水平的提高会导致实际均衡点立即下降。为了防止利率的上升可能引发的本币升值，中央银行必须购进外国货币，因而增加了货币供给。中央银行的这种行动是通过增加货币供给来满足最初的增加工资的要求，使经济永久性地向更高的工资与价格水平移动。实行固定汇率是无法使工资与价格下降的”。这种说法错在哪里？

A central bank that adopts a fixed exchange rate may sacrifice its autonomy in setting domestic monetary policy．It is sometimes argued that when this is the case，the central hank also gives up the ability to use monetary policy to combat the wage-price spiral．The argument goes like this：“Suppose workers demand higher wages and employers give in，but that the employers then raise output prices to cover their higher costs．Now the price level is higher and real balances are momentarily lower，so to prevent an interest rate rise that would appreciate the currency，the central bank must buy foreign exchange and expand the money supply．This action accommodates the initial wage demands with monetary growth and the economy moves permanently to a higher level of wages and prices．With a fixed exchange rate there is thus no way of keeping wages and prices down.” What is wrong with this argument？