Question

This week, I ask that you identify three interrelated markets that allows you to demonstrate your understanding of when an event causes movement along the demand curve (a change in quantity demand), and when an event causes the demand curve to shift completely (a change in demand). 
For example, consider the demand for Hot Dogs, Hot Dog Buns (a complement of hot dogs), and Hamburgers (a substitute for hamburgers).
Now, for some reason, the price of hot dogs decline.  What impact will this have in the three markets?
1)  In the hot dog market, a decline in price of the hot dogs (notice same market) will cause movement along the demand curve.  As the price falls, the quantity demanded increases. It is shows by moving to a point that is lower and to the right of the original curve.  
2)  In the hot dog BUN market, a decline in price of HOT DOGS (notice different market) will cause an increase in demand for hot dog buns (because they are complements).  It is shown by a shift in right of the demand curve.
3) In the Hamburger market, a decline in price of HOT DOGS (note different market) will cause a decrease in demandfor hamburgers (because hot dogs and hamburgers are substitutes).   It is shown a shift to the left of the demand curve.
Your assignment:
Identify three related goods.  Demonstrate ONE change that causes a movement along a demand curve, and the SAME CHANGE causes shifts in two other markets (think complement and substitute).  Describe your markets. 

Answer 1