1a). Why does a reduction in aggregate demand in the actual economy reduce real output, rather than the price level?

1b). Why might a full-strength multiplier apply to a decrease in aggregate demand?

2a). What assumptions cause the immediate-short-run aggregate supply curve to be horizontal? Why is the long-run aggregate supply curve vertical?

2b). Explain the shape of the short-run aggregate supply curve.

3c). Why is the short-run aggregate supply curve relatively flat to the left of the full-employment output and relatively steep to the right?