Qunatity supply is changed with the change in price of good concerned when all other factors which determine demand remain constant.
If all other factors which determine supply, are constant , increase in price causes to the quantity supply to decreases, then a point on the supply curve movesdownwards along supply curve.
When all other factors which determine supply, the increase in price causes increase in quantity supply and a point on the supply curve moves upwords along the supply curve.
Decrease in supply or increase in supply happens if all other factors change while the price of the good concerned is constant. Increase in supply causes the supply curve to shift to the right.
The following reasons causes the supply curve to shift to the right.
Decrease in price of related good
Decrease in price of production inputs
Improvements of technology
Expecting a price increase of a good concerned in the future.
Increase in the number of producers in a market.
Providing subsidies to producer by the government.
The supply curve will shift to the left when the supply decreases.
The following reasons cause the supply curve to shift to the left.
Increase in the price of related good.
Increase in the price of production inputs
Deterioration of technology
Expecting a price decrease of good concerned in the future.
Decrease in the number of producers in the market.
Imposition of taxes on goods and services by the government.
