An Increase in Demand
Demand changes for any of the five reasons listed 
in the previous section.
When the demand curve shifts to the right demand increases. The market price increases, as does the equilibrium quantity (in the short run).
A Decrease in Demand
When the demand curve shifts to the left, equilibrium price and quantity decrease (in the short run).
Video Explanation
For a video explanation of how a change in buyers’ incomes changes the demand (and the equilibrium price and quantity) for a normal good, please visit:
For a video explanation of how a change in buyers’ incomes changes the demand (and the equilibrium price and quantity) for a normal good, please visit: