First, it is important differentiate between:
1. Change in quantity demanded vs. Change in Demand
2. Change in quantity supplied vs. Change in Supply
The terminology is important to get straight because some questions will say the quantity demanded
changed and others will say there was a change in demand.
If after reading the chapter remain confused you might want to watch the 5 min video below. Also, I
found a table from Google in which they summarize the main differences.
Remember that a change in QD refers to a movement along the line and is caused by changing the price
of the good.
Whereas, a change in Demand refers to the entire line shifting, and is caused by one of the factors (or
determinants) changing. The main factors are things like: a change in preferences, a change in consumer
income, a change in the price of a substitute product, a change in the price of a compliment good, and a
change in expectations.
https://www.youtube.com/watch?v=4KfnakHcLQk
Demand VS. Q.D.
Change in
Demand
Change in
Quantity
Demanded
