Change in Quantity Demanded vs. Change in Demand Chapter 4, Lesson Two

Change in Quantity Demanded Abbreviated ΔQd Change in Qd is represented as a movement along the demand curve and results from a change in price

                                                                                           Change in Qd

Change in Qd The only thing that will result in a Change in Qd is a change in price of the product we are talking about This is just a movement ALONG the curve that is already given—going from one point to another

                                                                                           Change in Qd

Change in Demand Abbreviated ΔD Change in D—a shift of the ENTIRE demand curve and it is caused when something changes the quantity of a product demanded at each price

Shift of Demand Versus Movement Along a Demand Curve A change in demand is not the same as a change in quantity demanded. In this example, a higher price causes lower quantity demanded. Changes in determinants of demand, other than price, cause a change in demand, or a shift of the entire demand curve, from DA to DB.

A Change in Demand Versus a Change in Quantity Demanded When demand shifts to the right, demand increases. This causes quantity demanded to be greater than it was prior to the shift, for each and every price level.

Change in D This is when you get an entirely NEW curve, so each point has changed. Now people are demanding more or less of the product at each price. Can you think of anything that would do this? What would cause you to buy more or less bottled water, even though the price of the bottled water stays the same?

Change in Demand Determinants of Demand—things that will cause a change in D --A change in the price of substitutes --A change in the price of complements --A change in consumer income --A change in population --A change in consumer tastes --A change in consumer expectations

Increases in Demand The entire demand curve shifts RIGHT. (Demand curves only shift RIGHT or LEFT, never UP or DOWN!) This is because at each given price there is now more quantity demanded. To show there is an increase in quantity, we move RIGHT because our quantity axis increases as we move further to the right.

A Change in Demand Versus a Change in Quantity Demanded When demand shifts to the right, demand increases. This causes quantity demanded to be greater than it was prior to the shift, for each and every price level.

Decreases in Demand The entire demand curve shifts LEFT. This is because at each given price there is now less quantity demanded. To show there is a decrease in the quantity, we move left because our quantity axis decreases as we move further to the left.

Website that Allows you to see the Difference http://www.amosweb.com/cgi-bin/awb_nav.pl?s=wpd&c=dsp&k=change+in+quantity+demanded