We have looked at the effect of changing tastes, income, prices of related goods and expectations on demand. There are, of course, other reasons that demand curves will shift: changes in population characteristics such as size, age distribution, life expectancy; changes in the legal status of some products; introduction of new products and so on.
Demand shifts aren't mysterious. Anything that affects demand behavior, other than a change in the price of the good or service in question, will shift the demand curve.
Below is a table briefly summarizing what we've learned about demand curve shifts. It may be useful as a quick review to be sure you can explain to yourself the reason for each demand shift in the table below.
|Normal Good||Income Rises||Demand Shifts Out|
|Normal Good||Income Falls||Demand Shifts Back|
|Inferior Good||Income Rises||Demand Shifts Back|
|Inferior Good||Income Falls||Demand Shifts Out|
|Substitute||Price Rises||Demand Shifts Out|
|Substitute||Price Falls||Demand Shifts Back|
|Complement||Price Rises||Demand Shifts Back|
|Complement||Price Falls||Demand Shifts Out|
|Expect||Price Increase||Demand Shifts Out|
|Expect||Price Decrease||Demand Shifts Back|