1 market demand and supply ©2006 south-western college publishing
TRANSCRIPT
1
Market Demand and Supply
©2006 South-Western College Publishing
The Market Forces of Supply and Demand
Supply and demand are the two words that economists use most often.
Supply and demand are the forces that make market economies work.
Modern microeconomics is about supply, demand, and market equilibrium.
Markets
A market is a group of buyers and sellers of a particular good or service.
The terms supply and demand refer to the behavior of people . . . as they interact with one another in markets.
Markets Buyers determine demand.
Sellers determine supply.
Market Type: A Competitive Market
A competitive market is a market. . .
with many buyers and sellers.
that is not controlled by any one person.
in which a narrow range of prices are established that buyers and sellers act upon.
Competition: Perfect and Otherwise
Products are the same Numerous buyers and sellers so that
each has no influence over price Buyers and Sellers are price takers
Perfect Competition
Competition: Perfect and Otherwise
Monopoly One seller, and seller controls price
Oligopoly Few sellers Not always aggressive competition
Competition: Perfect and Otherwise
Monopolistic Competition Many sellers Slightly differentiated products Each seller may set price for its own
product
9
What is demand?
Demand represents the choice making behavior of buyers
Demand Schedule
Price Quantity$0.00 120.50 101.00 81.50 62.00 42.50 23.00 0
Law of Demand
The law of demand states that there is an inverse
relationship between price and quantity demanded.
12
What is a demand curve?
Depicts the relationship between price and quantity demanded
13
Why do demand curves have a negative slope?At a higher price buyers will buy fewer units, and at a lower price they will buy more units
Ceteris Paribus
Ceteris paribus is a Latin phrase that means all variables other than the
ones being studied are assumed to be constant. Literally, ceteris
paribus means “other things being equal.”
The demand curve slopes downward because, ceteris paribus, lower prices
imply a greater quantity demanded!
15
Market Demand
Market demand refers to the sum of all individual demands for a particular good or service.
Graphically, individual demand curves are summed horizontally to obtain the market demand curve.
16
IMPORTANT - KNOW THE DIFFERENCE BETWEEN A CHANGE IN THE QUANTITY DEMANDED AND A CHANGE IN DEMAND
17
When price changes, what happens?
The curve does not shift - there is a change in
the quantity demanded
18
Change in Price
Change in Quantity
Demanded
19
When something changes other than
price, what happens?The whole curve
shifts,there is a change in demand
20
What can cause a demand curve to shift?
A change in:• Number of buyers in the market• Tastes and preferences• Income• Expectations of consumers• Prices of related goods
21
Change in a Nonprice
determinant
Leftward or rightward shift in
the demand curve
Decrease or increase in
demand
22
Why does Sunkist http://www.sunkist.com, a major producer of oranges, provide free orange recipes? To increase the demand for oranges, of course
Consumer Income
As income increases the demand for a normal good will increase.
As income increases the demand for an inferior good will decrease.
24
What aresubstitute goods?
Goods that compete with one another for consumer purchases
25
What happens when the price increases for
a good that has a substitute?
The demand curve for the substitute good increases
26
What happens when the price decreases for
a good that has a substitute?
The demand curve for the substitute good decreases
27
What does a direct relationship
between price and quantity mean?
The two move in the same direction
28
What are complementary goods?
Goods that are jointly consumed with another good
29
What happens when the price increases for
a good that has a complement?
The demand curve for the substitute good decreases
30
What happens when the price decreases for
a good that has a complement?
The demand curve for the substitute good increases
31
What does an inverse relationship between
price & quantity mean? It means that the two move in opposite directions
32
What is supply?
Supply represents the choice making behavior of sellers
Supply Schedule
Price Quantity$0.00 00.50 01.00 11.50 22.00 32.50 43.00 5
34
What is thelaw of supply?
The principle that there is a direct relationship between the price of a good and the quantity sellers are willing to offer for sale in a defined time period, ceteris paribus
35
Why do supply curves have a positive slope?
Only at a higher price will it be profitable for sellers to incur the higher opportunity cost associated with supplying a larger quantity
36
What is market supply?
The horizontal summation of all the quantities supplied at various prices that might prevail in the market
37
IMPORTANT - KNOW THE DIFFERENCE BETWEEN A CHANGE IN THE QUANTITY SUPPLIED AND A CHANGE IN SUPPLY
38
When price changes, what happens?
The curve does not shift - there is a change in the quantity supplied
39
Change in Price
Change in Quantity Supplied
40
When something changes other than
price, what happens?The whole curve shifts -
there is a change in supply
41
Change innonprice
determinant
Change in supply
42
What can cause a supply curve to shift?
A change in:• Number of sellers in the market• Technology• Resource prices• Taxes and subsidies• Expectations of producers• Prices of other goods the firm
could produce
43
What is the equilibrium price?
The price towards which the economy tends
44
Where is the equilibrium price?
At the price where the quantity demanded and the quantity supplied are equal
45
Surplus
When the price is above the equilibrium price, the quantity supplied exceeds the quantity demanded. There is excess supply or a surplus. Suppliers will lower the price to increase sales, thereby moving toward equilibrium.
46
Shortage
When the price is below the equilibrium price, the quantity demanded exceeds the quantity supplied. There is excess demand or a shortage. Suppliers will raise the price due to too many buyers chasing too few goods, thereby moving toward equilibrium.
Steps To Analyzing Changes in Equilibrium
Determine the Event Decide whether the event shifts the supply or
demand curve (or both in very rare cases). Shift demand or supply to the left or to the
right. (Make a cheat sheet!) Find the new equilibruim Examine how the shift affects equilibrium
price and quantity.