第35章通货膨胀与失业之间的短期权衡取舍.ppt

通货膨胀与失业之间的短期权衡取舍 * 结论 本章的理论是20世纪许多最优秀的经济学家的思想 他们告诉我们通货膨胀与失业率： 在长期中是无关的 短期中是负相关的 受预期影响，预期在经济从短期向长期调整过程中起着相当重要的作用 内容提要 菲利普斯曲线描述了通货膨胀与失业之间的短期权衡取舍 在长期中，通货膨胀与失业之间并不存在权衡取舍：通货膨胀率取决于货币增长率，而失业率等于自然失业率 供给冲击与预期通货膨胀的变动会使短期菲利普斯曲线发生移动，从而给决策者一个更有利或不利的通货膨胀和失业之间的权衡取舍 * 内容提要 当美联储紧缩货币供给增长以降低通货膨胀时，它使经济沿着短期菲利普斯曲线移动，这就引起暂时的高失业。然而在长期中，预期调整与现实一致，失业率回到自然率 一些经济学家认为，可信任的低通货膨胀承诺可以通过引起预期的迅速调整而降低反通货膨胀的代价 * This chapter traces the history of economists’ thinking about the relationship between inflation and unemployment. It is the last of a three-chapter sequence on short-run economic fluctuations. It builds on three key elements of the preceding two chapters: 1) The upward-sloping SRAS curve, and how it shifts in response to changes in expectations 2) The ability of monetary policy to shift the AD curve and affect real variables in the short run 3) The classical dichotomy, long-run monetary neutrality, and vertical LRAS curve While this chapter is not easy, most students find it less difficult than the two preceding chapters. * “Suppose P = 100 this year” provides an anchor to the analysis in the graphs on the following slide. At this point, remind students that output and unemployment are negatively related over business cycles (one of the “three facts about economic fluctuations” from the chapter entitled “aggregate demand and aggregate supply”). * Assume P = 100 this year. If aggregate demand next year is low – reflecting, for example, slow money growth – then outcome A will occur next year. In outcome A, P = 103 next year, so the inflation rate from this year to next equals 3%. Output (Y1) is relatively low, so unemployment is relatively high at 6%. Instead, if aggregate demand next year is high – reflecting, for example, rapid money growth – then outcome B will occur next year. In outcome B, P = 105 next year, so the inflation rate from this year to next equals 5%. Output (Y2) is higher, so unemployment is lower (4%). The data almost perfectly trace out a downwa