A shift in supply results when the quantity supplied is affected by a factor other than price.

The figure shows a decrease in supply between Supply 1 and Supply 2, with no change in price.

Changes in natural conditions (such as rainfall and environmental conditions), or technology may shift the supply curve also.

A supply shift might occur when the supply of Saskatoon berries decreases in a year with too much or too little rain, but the price of Saskatoon jam doesn't change.