Editing Supply and demand (section)

====Supply curve shifts====
{{Main|Supply (economics)}}
[[File:Supply-demand-right-shift-supply.svg|thumb|Right-shift of [[Supply (economics)|supply curve]] decreases price and increases quantity.]]
When technological progress occurs, the supply curve shifts.  For example, assume that someone invents a better way of growing wheat so that the cost of growing a given quantity of wheat decreases. <!-- DO NOT wikilink "wheat" as this is contrary to Wikipedia:Manual of Style/Linking#An example article -->  Otherwise stated, producers will be willing to supply more wheat at every price and this shifts the supply curve {{math|''S''<sub>1</sub>}} outward, to {{math|''S''<sub>2</sub>}}—an ''increase in supply''. This increase in supply causes the equilibrium price to decrease from {{math|''P''<sub>1</sub>}} to {{math|''P''<sub>2</sub>}}. The equilibrium quantity increases from {{math|''Q''<sub>1</sub>}} to {{math|''Q''<sub>2</sub>}} as consumers move along the demand curve to the new lower price. As a result of a supply curve shift, the price and the quantity move in opposite directions.  If the quantity supplied ''decreases'', the opposite happens. If the supply curve starts at {{math|''S''<sub>2</sub>}}, and shifts leftward to {{math|''S''<sub>1</sub>}}, the equilibrium price will increase and the equilibrium quantity will decrease as consumers move along the demand curve to the new higher price and associated lower quantity demanded. The quantity demanded at each price is the same as before the supply shift, reflecting the fact that the demand curve has not shifted. But due to the change (shift) in supply, the equilibrium quantity and price have changed.

The movement of the supply curve in response to a change in a non-price determinant of supply is caused by a change in the y-intercept, the constant term of the supply equation. The supply curve shifts up and down the y axis as non-price determinants of demand change.