曼昆《经济学原理》(宏观经济学分册)英文原版课件——35shortrun.pptVIP

35 The Short-Run Tradeoff between Inflation and Unemployment Unemployment and Inflation The natural rate of unemployment depends on various features of the labor market. Examples include minimum-wage laws, the market power of unions, the role of efficiency wages, and the effectiveness of job search. The inflation rate depends primarily on growth in the quantity of money, controlled by the Fed. Unemployment and Inflation Society faces a short-run tradeoff between unemployment and inflation. If policymakers expand aggregate demand, they can lower unemployment, but only at the cost of higher inflation. If they contract aggregate demand, they can lower inflation, but at the cost of temporarily higher unemployment. THE PHILLIPS CURVE The Phillips curve illustrates the short-run relationship between inflation and unemployment. Figure 1 The Phillips Curve Aggregate Demand, Aggregate Supply, and the Phillips Curve The Phillips curve shows the short-run combinations of unemployment and inflation that arise as shifts in the aggregate demand curve move the economy along the short-run aggregate supply curve. Aggregate Demand, Aggregate Supply, and the Phillips Curve The greater the aggregate demand for goods and services, the greater is the economy’s output, and the higher is the overall price level. A higher level of output results in a lower level of unemployment. Figure 2 How the Phillips Curve is Related to Aggregate Demand and Aggregate Supply SHIFTS IN THE PHILLIPS CURVE: THE ROLE OF EXPECTATIONS The Phillips curve seems to offer policymakers a menu of possible inflation and unemployment outcomes. The Long-Run Phillips Curve In the 1960s, Friedman and Phelps concluded that inflation and unemployment are unrelated in the long run. As a result, the long-run Phillips curve is vertical at the natural rate of unemployment. Monetary policy could be effective in the short run but not in the long run. Figure 3 The Long-Run Phillips Curve Figure 4 How the Phillips Curve is Relat