The neoclassical long-run aggregate supply curve implies the Phillips curve is a vertical shape indicating there is no long-run tradeoff between inflation and unemployment. Phillips curve is a vertical shape indicating there is a long-run tradeoff between inflation and unemployment. Phillips curve is an upward sloping curve indicating there is no long-run tradeoff between inflation and unemployment. Phillips curve is a downward sloping curve indicating there is a long-run tradeoff between inflation and unemployment