How is the long-run Phillips Curve characterized in comparison to the short-run Phillips Curve?

The long-run Phillips Curve is characterized as being vertical at the natural rate of unemployment. This reflects the idea that in the long run, there is no trade-off between inflation and unemployment. According to the expectations-augmented Phillips Curve, in the long run, any attempts to reduce unemployment below its natural rate will lead to accelerating inflation, as people adjust their expectations of inflation.

This contrasts with the short-run Phillips Curve, which is typically depicted as downward sloping, showing an inverse relationship between inflation and unemployment. In the short run, policymakers can exploit this trade-off, but it does not hold in the long run due to adaptive expectations. Thus, while the short-run Phillips Curve suggests that lower unemployment can come with higher inflation (or vice versa), the long-run view implies that we will always return to the natural rate, regardless of inflation levels, resulting in a vertical line on the graph.