What kind of table lists the quantity of a good that a person will buy at different prices?

Non-price determinants of demand

The non-price factors that will determine demand and can cause a shift of the demand curve

The demand curve itself can shift left (decreased demand) or shift right (increased demand). See figure 3 below. The five factors that determine demand, and thus, increase or decrease demand are:

• Income
• Preferences, tastes and fashion
• Price of related goods
• Future price expectations
• Demographic changes

Essential statement: A change in quantity demanded is only caused by a change in the price of a good or service, and is shown by a movement along the demand curve. A change in demand shifts the demand curve up (an increase) and right or down and left (a decrease) and is only caused by a change in one or more of the factors that determine demand.

Tastes and preferences

As goods and services become more desirable demand grows. The demand curve moves up and right to indicate that quantity demanded also increases at each price, and when it gets to be less desirable, demand declines. The demand curve shifts down and left to indicate that less is demanded at each price.

For example, as Apple’s iPhone became preferred by a large segment of consumers, demand for it increased (the demand curve shifted right). Conversely, as Blackberry phones fell out of favour, demand for their phones decreased (the demand curve shifted left).

The price of related goods

Substitutes are products you can use instead of a different good or service (e.g., Coke and Pepsi are substitutes, so too are petrol and public bus rides.
A rise in the price of petrol results in a rise in quantity demanded of bus rides at each price and the demand curve for bus rides moves up and right.

Complements are products that are used and consumed with each other (e.g., smartphones and apps). Once the cost of smartphones falls the quantity demanded of this good increases. Extra apps are then sold. Demand for apps increases as the price of smartphones decreases. Additional apps are required at each fall in the price of smartphones, and the demand curve for apps moves up and right.

What is a substitute good?

What is a complement good?

Income

Normal goods are goods and services for which demand increases as consumers' income increases and for which demand goes down when income is lower. Examples include new cars and holidays.
 
Demand for normal goods will increase as consumers’ income increases. The demand curve shifts up and right to illustrate that more of the good or service is required at each price.
 
Inferior goods are those goods and services for which demand tends to fall when income rises. Examples would include used cars and cheaper cuts of meat. Demand for inferior goods decreases when income increases. The demand curve moves down and left to indicate less is required at each price.
Every buyer responds in different ways to an adjustment in income. A good or service that is considered ‘inferior’ for one individual might not be for another.

What is a normal good?

What is an inferior good?

changing numbers of consumers

Demographic changes. These are variations in the attributes of the population (size, age, proportion of women in the workforce). As the population grows quantity demand for the majority of products rises at each price and the demand curve shift up and right. For example, as the population of New Zealand grew from 3.5 million in 1991 to 5 million in 2020, the extra 1.5 million consumers increased the demand for almost all goods and services in the market.

Changes in the composition of the population.The proportion of elderly citizens in the United States population is rising. It rose from 9.8% in 1970 to 12.6% in 2000, and will be a projected (by the U.S. Census Bureau) 20% of the population by 2030. A society with relatively more children, like the United States in the 1960s, will have greater demand for goods and services like tricycles and day care facilities. A society with relatively more elderly persons, as the United States is projected to have by 2030, has a higher demand for nursing homes and hearing aids. Similarly, changes in the size of the population can affect the demand for housing and many other goods. Each of these changes in demand will be shown as a shift in the demand curve.​

Future price expectations

The decision to purchase a good today depends on expectations of future prices. Buyers seek to purchase a good at the lowest possible price. If they expect the price to rise in the future, they are inclined to buy more now. If buyers expect the price to decline in the future, they are inclined to buy less now.

Looking to the future. Buyers make buying decisions based on a comparison of current and future prices. They are motivated to purchase the good at the lowest price possible. If that lowest price is the one existing today, then they will buy today. If that lowest price is expected to occur in the future, then they will wait until later to buy.
​
Consider the example of Wacky Willy Stuffed Amigos, a cute and cuddly line of stuffed creatures. Buyers decide how many Stuffed Amigos to buy, at a given current price, based on their expectations of future prices.

Price going higher: Suppose that news media throughout the country report on the prospects of a worldwide shortage of stuffing, the same sort of stuffing used to stuff Wacky Willy Stuffed Amigos. Every expert interviewed projects that the higher stuffing prices will most assuredly cause an increase in the price of Stuffed Amigos. The price increase has not yet occurred, but it most assuredly will occur. Everyone expects it to occur. With this news, anyone pondering the purchase of Wacky Willy Stuffed Amigos will be inclined to make their purchase now, without delay. As such, the current demand increases.

Price going lower: Alternatively, suppose that The Wacky Willy Company, the firm that produces Wacky Willy Stuffed Amigos announces that it has developed a new production technique, that when implemented will allow them to sell Stuffed Amigos at half their current price. This news is greeted enthusiastically by Stuffed Amigos collectors. They expect to purchase Stuffed Amigos at a lower price in the near future. With this news, anyone pondering the purchase of Wacky Willy Stuffed Amigos today will likely postpone their purchase until later, at the lower price. As such, the current demand decreases.