## Demand

Read this section to learn about the theory of demand. Attempt the "Try It" problem. Use the data from the text to practice constructing and drawing the demand curve on your own, either on a paper or in Excel. Take a moment to read through the stated learning outcomes for this chapter of the text, which you can find at the beginning of each section.

### Key Takeaways

• The quantity demanded of a good or service is the quantity buyers are willing and able to buy at a particular price during a particular period, all other things unchanged.
• A demand schedule is a table that shows the quantities of a good or service demanded at different prices during a particular period, all other things unchanged.
• A demand curve shows graphically the quantities of a good or service demanded at different prices during a particular period, all other things unchanged.
• All other things unchanged, the law of demand holds that, for virtually all goods and services, a higher price induces a reduction in quantity demanded and a lower price induces an increase in quantity demanded.
• A change in the price of a good or service causes a change in the quantity demanded – a movement along the demand curve.
• A change in a demand shifter causes a change in demand, which is shown as a shift of the demand curve. Demand shifters include preferences, the prices of related goods and services, income, demographic characteristics, and buyer expectations.
• Two goods are substitutes if an increase in the price of one causes an increase in the demand for the other. Two goods are complements if an increase in the price of one causes a decrease in the demand for the other.
• A good is a normal good if an increase in income causes an increase in demand. A good is an inferior good if an increase in income causes a decrease in demand.