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Changes in Expectations about Future Prices or Other Factors that Affect Demand

While it is clear that the price of a good affects the quantity demanded, it is also true that expectations about the future price (or expectations about tastes and preferences, income, and so on) can affect demand. For example, if people hear that a hurricane is coming, they may rush to the store to buy flashlight batteries and bottled water. If people learn that the price of a good like coffee is likely to rise in the future, they may head for the store to stock up on coffee now. These changes in demand are shown as shifts in the curve. Therefore, a shift in demand    happens when a change in some economic factor (other than price) causes a different quantity to be demanded at every price. The following Work It Out feature shows how this happens.

Shift in demand

A shift in demand means that at any price (and at every price), the quantity demanded will be different than it was before. Following is an example of a shift in demand due to an income increase.

Step 1. Draw the graph of a demand curve for a normal good like pizza. Pick a price (like P 0 ). Identify the corresponding Q 0 . An example is shown in [link] .

Demand curve

The graph represents the directions for step 1.A demand curve shows how much consumers would be willing to buy at any given price.
The demand curve can be used to identify how much consumers would buy at any given price.

Step 2. Suppose income increases. As a result of the change, are consumers going to buy more or less pizza? The answer is more. Draw a dotted horizontal line from the chosen price, through the original quantity demanded, to the new point with the new Q 1 . Draw a dotted vertical line down to the horizontal axis and label the new Q 1 . An example is provided in [link] .

Demand curve with income increase

The graph represents the directions for step 2. With an increased income, consumers will wish to buy a higher quantity (Q sub 1) than they bought with a lower income.
With an increase in income, consumers will purchase larger quantities, pushing demand to the right.

Step 3. Now, shift the curve through the new point. You will see that an increase in income causes an upward (or rightward) shift in the demand curve, so that at any price the quantities demanded will be higher, as shown in [link] .

Demand curve shifted right

The graph represents the directions for step 3. An increased income results in an increase in demand, which is shown by a rightward shift in the demand curve.
With an increase in income, consumers will purchase larger quantities, pushing demand to the right, and causing the demand curve to shift right.

Summing up factors that change demand

Six factors that can shift demand curves are summarized in [link] . The direction of the arrows indicates whether the demand curve shifts represent an increase in demand or a decrease in demand. Notice that a change in the price of the good or service itself is not listed among the factors that can shift a demand curve. A change in the price of a good or service causes a movement along a specific demand curve, and it typically leads to some change in the quantity demanded, but it does not shift the demand curve.

Factors that shift demand curves

The graph on the left lists events that could lead to increased demand. The graph on the right lists events that could lead to decreased demand.
(a) A list of factors that can cause an increase in demand from D 0 to D 1 . (b) The same factors, if their direction is reversed, can cause a decrease in demand from D 0 to D 1 .

When a demand curve shifts, it will then intersect with a given supply curve at a different equilibrium price and quantity. We are, however, getting ahead of our story. Before discussing how changes in demand can affect equilibrium price and quantity, we first need to discuss shifts in supply curves.

Questions & Answers

what is the price of elasticity of demand
Mahesh Reply
what is per capita income
Kafwimbi Reply
what is GDP of an economy
Gross Domestic Product
Why is scarcity the main problem of economics
Nicholas Reply
Because of unlimited needs and wants demanded by the household
what is GDP deflator?
Because of endless needs and wants required to achieve maximum satisfaction possible by consumers
how to calculate price elasticity demand?
Precious Reply
change in quantity over quantity divided by change in price over price
Percentage change in quantity demanded over the percentage change in price
if the local pizzeria raises the price of a medium pizza from Rd.60to 100 & quantity demanded falls from 700 pizzas a night to 100 pizzas at night , the price elasticity of demand for pizzas is:
Lakshmi Reply
1.2. Measurement of price Elasticity of demand
Lakshmi tell me how wrong am I coz I see you've got different answer from mine?
explain how price and output are determind by a discriminating monopolist
Hiraj Reply
price and output determined through interaction between demand curve and supply curve...
how do I view the graphs
Patricia Reply
how do I open the links
what is the markert
Ester Reply
A market is any place where buying and selling can take place.
20. Why is a football game on ESPN a quasi-public good but a game on the NBC, CBS, or ABC is a public good?
Brigam Reply
how people make decision?
Xafsa Reply
what is supply and demand
Xafsa Reply
Demand refers to how much (quantity) of a product or service is desired by buyers. The quantity demanded is the amount of a product people are willing to buy at a certain price.
thank you very much
list and briefly explain the three principles that describe how the economy as whole works?
what is algebra?
ibiflower Reply
what is the relationship between price and demand
Evans Reply
the relation ship between price and demand is the income and Utility means when you are satisfied and you can buy it then you have to demand it.Thanks
who thought u that? you are not answering this as an economist
alright, but can you tell how the economist will be answered
alright, but can you tell me how the economist will be answered
Law of demanded  states: As price  of a good increases, the quantity demanded  of the good falls, and as the price  of a good decreases, the quantity demanded of the good rises.
So, there is an inverse relationship between price and demand.
lewis answered it perfectly
I want for market value for price. or cleance
time ticket of value market down so double be self 1.09 but I 10 chesse for 1.09 bugger
Without scarcity there would be no subject call Economics. Explain why?
because economics is the study of scarcity of resources and the satisfaction of basic human need
give an example of some action that has both amonetary and nonmonetary apportunity cost?
Aisha Reply
any action can be argued to have both. For instance, being in class has the opportunity cost of time you could be spent earning wages, or time that could've been spent leisurely.
there is no any action that hasn't both a monetary and non-monetary as said Mr Dasrat
u Welcome
describe an important trade-off you recently faced?
Aisha Reply
Financial issues and careerPersonal life and work lifeMost people don't like the work they do. The interest they have is something different from the work they do and eventually forgo their interest. These are the three most important tradeoffs I have come across, yet there may be many in number.
Yah still

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Source:  OpenStax, Microeconomics. OpenStax CNX. Aug 03, 2014 Download for free at http://legacy.cnx.org/content/col11627/1.10
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