Question

Difference between contraction of supply and decrease in supply

Answer 1

Decrease in Supply(Shift of the Supply curve to the left)Contraction of Supply
When we say there is a shift in the supply curve to the left then it means the entire supply curve has shifted to the left side.  The supply curve shifts to the left when there are changes in factors other than the price of the product resulting in decrease in supply. 

Let us take an example of biscuits. If there is rise in the price of inputs then the cost of production will increase. Due to this the producers may supply less biscuits in the market. This will lead to decrease in the supply of biscuits thereby shifting the supply curve of biscuits inwards (to the left).   The decrease in supply is shown with the help of two supply curves.     
Contraction of supply shows the changes on the same supply curve. Here there is a downward movement along the same supply curve. Contraction of supply occurs when there is a fall in the price of the product. Here the impact of price fall is plotted on the same supply curve.   If there is fall in the price of biscuits then this will lead to less supply of biscuits in the market.  Here the only reason being the price (all the other factors are kept constant) will cause the variation (fall) in supply.     Contraction in supply is shown on the same supply curve.