Change in Demand vs. Change in Quantity Demanded
… a core concept in Economic Analysis
In his MRU lesson, Alex Tabarrok (reference below and video to right) underlines the crucial distinction between a change in demand (a shift in the demand curve caused by one of the demand curve shifters) and a change in the quantity demanded (a movement along the same demand curve caused by a change in the price due to a change in supply).
This is illustrated in the figure. In the left graph the demand increases as a result of the shift in the demand curve. In the right graph the quantity demanded increases because increased supply (a shift of the green line to the right) has lowered the equilibrium price for the same demand curve.
MRU practice questions
See http://www.mruniversity.com/node/179639, accessed 20 April 2016:
- When supply falls, what happens to quantity demanded in equilibrium?
Alex Tabarrok, Supply and Demand Terminology, Marginal Revolution University, at http://www.mruniversity.com/courses/principles-economics-microeconomics/supply-demand-definition, accessed 20 April 2016.
Atlas topic and subject
Page created by: Ian Clark, last modified on 20 April 2016.
Image: Minute 1.48 of MRU Video, at http://www.mruniversity.com/courses/principles-economics-microeconomics/supply-demand-definition, accessed 20 April 2016.