Two Similar Curves

To reveal the similarities between the both curves, click the [Market Supply] and [Aggregate Supply] buttons. Doing so illustrates that both curves are positively sloped, with each virtually overlaying the other.

Consider the differences between these two curves.

• First, note that for the market supply curve, the vertical axis measures supply price and the horizontal axis measures quantity supplied. For the short-run aggregate supply curve, however, the vertical axis measures the price level (GDP price deflator) and the horizontal axis measures real production (real GDP).


• Second, the positive slope of the market curve reflects the law of supply and is attributable to the law of diminishing marginal returns. In contrast, the positive slope of the short-run aggregate supply curve is attributable to: (1) inflexible resource prices that often makes it easier to reduce aggregate real production and resource employment when the price level falls, (2) the pool of natural unemployment, consisting of frictional and structural unemployment, that can be used temporarily to increase aggregate real production when the price level rises, and (3) imbalances in the purchasing power of resource prices that can temporarily entice resource owners to produce more or less aggregate real production than they would at full employment. Similar, but different.