Classical Versus Keynesian MacroeconomicsOne important difference between classical and Keynesian economics involves the short-run aggregate supply curve. Panel (a) shows the classical view: the SRAS curve is vertical, so shifts in aggregate demand affect the aggregate price level but not aggregate output. Panel (b) shows the Keynesian view: in the short run the SRAS curve slopes upward, so shifts in aggregate demand affect aggregate output as well as aggregate prices.