解答这道题目---PROBLEM Suppose that a temporary increase in oil prices creates an inflationary shock and reduces potential output. Use an AD-AS diagram to show the effects of the oil price increase on output and inflation in the short-run and the long-run, assuming that there is no policy response. (5 marks) Suppose now that the increase in oil prices becomes permanent. Use an AD-AS diagram to show the effects of the oil price increase on output and inflation in the short-run and the long-run, assuming that there is no policy response. What happens if the Reserve Bank responds to the oil price increase by tightening monetary policy? (5 marks)

视频信息

答案文本 复制

视频字幕 复制

Oil price increases are typical supply shocks that have important effects on the macroeconomy. We use the AD-AS model to analyze these shock effects. Initially, the economy is in long-run equilibrium where the aggregate demand curve AD, short-run aggregate supply curve SRAS, and long-run aggregate supply curve LRAS intersect at potential output Yp and price level P0. A temporary oil price increase acts as a negative supply shock. In the short run, higher oil prices increase production costs, shifting the SRAS curve leftward. This creates stagflation - output falls below potential while the price level rises. However, since the oil price increase is temporary, in the long run prices return to normal, the SRAS curve returns to its original position, and the economy returns to potential output. A permanent oil price increase has more severe long-term consequences. In the short run, we see the same effects as before - SRAS shifts left causing stagflation. However, since the price increase is permanent, it also reduces the economy's long-run productive capacity. The LRAS curve shifts left, establishing a new long-run equilibrium with permanently lower output and higher prices. If the Reserve Bank responds to the oil price shock by tightening monetary policy, this shifts the AD curve leftward. While this may help combat inflation by reducing the price level somewhat, it comes at the cost of further reducing output and employment. The central bank faces a difficult trade-off between fighting inflation and supporting economic activity during a supply shock. 临时性石油价格上涨是典型的负向供给冲击。短期内，石油价格上升增加了生产成本，使短期总供给曲线向左移动。这造成了滞胀现象——产出下降至潜在产出以下，同时价格水平上升。然而，由于石油价格上涨是临时性的，长期来看价格会回归正常，短期总供给曲线会回到原始位置，经济最终回到潜在产出水平。 永久性石油价格上涨具有更严重的长期后果。短期内，我们看到与之前相同的效应——短期总供给曲线向左移动造成滞胀。然而，由于价格上涨是永久性的，它也降低了经济的长期生产能力。长期总供给曲线向左移动，建立了一个产出永久性降低、价格更高的新长期均衡。最终，短期总供给曲线会调整到新的长期均衡位置。 如果央行通过收紧货币政策来应对石油价格冲击，这会使总需求曲线向左移动。虽然这可能通过在一定程度上降低价格水平来帮助对抗通胀，但代价是进一步降低产出和就业。央行在供给冲击期间面临对抗通胀和支持经济活动之间的艰难权衡。这种政策响应展示了宏观经济政策制定的复杂性。 通过AD-AS模型分析，我们可以清楚地看到石油价格冲击对宏观经济的复杂影响。临时性冲击虽然在短期造成滞胀，但长期内经济会自然回归均衡。永久性冲击则更为严重，不仅造成短期滞胀，还会永久性降低经济的生产能力。货币政策虽然可以帮助对抗通胀，但代价是进一步的产出下降。这提醒我们，面对供给冲击时，政策制定者需要仔细权衡各种选择，而结构性改革可能是应对永久性冲击的更好方案。