Increase in Supply :
1. The supply is said to increase if at the same price more is supplied.
2. Increase in supply is a case of changes in supply.
3. Supply increases due to
(1) fall in cost of production
(2) improvement in transport facility
(3) introduction of modern technology
(4) government subsidies
(5) more imports etc.
4. When there is an increase in supply, the supply curve shifts to the right of original supply curve.

Decrease in Supply:
1. Decrease in supply occurs when less quantity is supplied at the same price.
2. It is a case of changes in supply.
3. Supply decreases due to:
(1) increase in cost of production
(2) transport strike
(3) outdated technique
(4) heavy taxes imposed by government.
(5) more exports etc.
4. When there is curve shifts to curve.
