The immediate-short-run aggregate supply curve assumes that both input prices and output prices are fixed. With output prices fixed, the aggregate supply curve is a horizontal line at the current price level. The short-run aggregate supply curve assumes nominal wages and other input prices remain fixed while output prices vary. The aggregate supply curve is generally upsloping because per-unit production costs, and hence the prices that firms must receive, rise as real output expands. The aggregate supply curve is relatively steep to the right of the full-employment output level and relatively flat to the left of it. The long-run aggregate supply curve assumes that nominal wages and other input prices fully match any change in the price level. The curve is vertical at the full-employment output level.