This graph is simply of a vertical long-run aggregate supply curve which runs parallel to the vertical price level axis. The original curve is labeled Yf on the horizontal real GDP line which symbolizes national output at full employment. There is a second vertical LRAS curve which runs parallel to the vertical price level axis and the original LRAS curve. This new LRAS curve is labeled Yf1 on the horizontal RGDP line. The new curve is located to the right of the original LRAS curve indicating that the economy is producing at a new level of efficiency. It is a manifestation of the movement of an economy outside the production possibilities frontier or PPF. The movement of the LRAS to the right might be in response to an improvement of resource quality, an improvement in resource quantity, or an enhancement in quality of one of the factors of production. The movement is generally gradual for example in the case of the increase of population following World War II. In that case, the LRAS shifted to the right as the new members of society became consumers, workers, and producers.
