Final answer:
The long-run Phillips curve's position is influenced by the natural rate of unemployment, implying that shifts in aggregate demand do not change this rate despite causing price level variations.
Step-by-step explanation:
The position of the long-run Phillips curve is determined by the natural rate of unemployment. Regardless of shifts in aggregate demand, whether from AD to AD₁ with a small inflationary increase or from AD to AD₂ with a larger inflationary increase, the natural rate of unemployment remains constant. This implies that the macroeconomic equilibrium on the vertical aggregate supply curve is established at different price levels without altering the natural rate. Notably, this is consistent with Milton Friedman's view that, although the trade-off between inflation and unemployment may be temporary, there is no permanent trade-off.