Download Demand - Research

Demand and Supply
តម្រូវការ​និងការផ្គតផ្់ ងគ ់
Learning Objectives
គោលបំណងននការសិក្សា
• How the demand curve summarizes the
behavior of buyers in the marketplace.
• How the supply curve summarizes the behavior
of sellers in the marketplace.
• How the supply and demand curves interact to
determine the equilibrium price and quantity.
• How shifts in supply and demand curves cause
prices and quantities to change.
What is the Market?
គតើអ្វីគៅដែលគៅថាទីផ្ារ?
•
•
Interaction between
buyers and sellers.
Markets may be
• Local
• National
• International
•
Price is discovered in
the interactions of
buyers and sellers.
Key Aspects of Markets
ទសសនៈសំខាន់ៗរបស់ទផ្ី ារ
Market Aspects
Why to Produce?
What to Produce ?
When to Produce?
Who will use the products?
How to Produce?
Where to Produce/Sell?
Demand (តម្រូវការ)
• Demand is defined as goods or services
that consumers are willing and ready to
pay/purchase at a given price.
– Schedule or curve
– Individual demand
– Market demand
– Demand Equation
Law of Demand
ច្បាប់របស់តម្រវូ ការ
• Other things equal, as price falls the quantity
demanded rises, and as price rises the quantity
demanded falls.
Notes:
P = Price
Qd = Quantity of Demand
The Demand Curve
ដសសគកាងតម្រវូ ការ
• Demand curve (D) a schedule or graph
showing the quantity of a good that buyers
wish to buy at each price.
The Demand Curve
ដសសគកាងតម្រវូ ការ
P
6
P Qd
$5 10
4 20
3 35
2 55
Price (per bushel)
5
4
3
2
1
D
1 80
0
10
20
30
40
50
60
70
80
Q
Quantity Demanded (bushels per week)
9
Shifts in Demand
បំដរបម្រលួ តម្រវូ ការ
• Change in demand a shift of the entire
demand curve.
• Change in the quantity demanded a
movement along the demand curve that
occurs in response to a change in price.
• Complements two goods are complements in
consumption if an increase in the price of one
causes a leftward shift in the demand curve for
the other (or if a decrease causes a rightward
shift)
• Substitutes two goods are substitutes in
consumption if an increase in the price of one
causes a rightward shift in the demand curve for
the other (or if a decrease causes a leftward
shift).
Determinants of Demand
ក្សត្តាជៈឥទធពិ លតម្រូវការ
Determinants of Demand: Factors That Shift the Demand Curve
Determinant
Examples
Change in buyers’
tastes/preferences
Physical fitness rises in popularity, increasing the
demand for jogging shoes and bicycles; cell phone
popularity rises, reducing the demand for land-line
phones.
Change in the number of buyers
A decline in the birthrate reduces the demand for
children’s toys.
Change in income
A rise in incomes increases the demand for normal
goods such as restaurant meals, sports tickets, and
necklaces while reducing the demand for inferior
goods such as cabbage, turnips, and inexpensive
wine.
13
Determinants of Demand (Con’t)
ក្សត្តាជៈឥទធពិ លតម្រូវការ
Determinants of Demand: Factors That Shift the Demand Curve
Determinant
Examples
Change in the prices of related
goods
A reduction in airfares reduces the demand for bus
transportation (substitute goods); a decline in the price
of DVD players increases the demand for DVD movies
(complementary goods).
Change in consumer
expectations
Inclement weather in South America creates an
expectation of higher future coffee bean prices,
thereby increasing today’s demand for coffee beans.
14
Supply (ការផ្គត់ផ្គង)់
•
•
•
•
Schedule or curve
Individual supply
Market supply
Supply Equation
Law of Supply
ច្បាប់របស់ការផ្គតផ្់ ងគ ់
• Other things equal, as price falls the quantity
supplied falls, and as price rises the quantity
supplied rises.
Notes:
P = Price
Qs = Quantity of Supply
Supply Equation
សរីការការផ្គតផ្់ ងគ ់
Notes:
C = intercept
b = slope
p = price
Qs = Quantity of Supply
The Supply Curve
ដសសគកាងការផ្គតផ្់ ងគ ់
• Supply curve (S) a graph or schedule
showing the quantity of a good that sellers
wish to sell at each price.
18
The Supply Curve
ដសសគកាងការផ្គតផ្់ ងគ ់
P
5
S
Supply of Corn
Qs
per
Week
$5
60
4
50
3
35
2
20
1
5
4
Price (per bushel)
Price
per
Bushel
3
2
1
0
10
20
30
40
50
60
70
Q
Quantity supplied (bushels per week)
19
Shifts in Supply
បំដរបម្រលួ ការផ្គតផ្់ ងគ ់
P
$6
Change in Quantity
S3
Supplied
S1
5
Price (per bushel)
S2
4
3
2
Change in Supply
1
0
2
4
6
8
10
12
14
Quantity supplied (thousands of bushels per week)
16 Q
Market Equilibrium
សរត្តទីផ្ារ
• Market equilibrium occurs in a market when all
buyers and sellers are satisfied with their
respective quantities at the market price.
Market Equilibrium
6
Surplus
S
P
Qd
$5
2,000
4
4,000
3
7,000
2
11,000
1
16,000
Price (per bushel)
5
4
3
2
Shortage
1
0
P
Qs
$5
12,000
4
10,000
3
7,000
2
4,000
1
1,000
D
2
4
67
8
10
12
14
16
18
Bushels of Corn (thousands per week)
22
Market Equilibrium
សរត្តទីផ្ារ
• Excess supply (Surplus) the amount by which
quantity supplied exceeds quantity demanded
when the price of a good exceeds the
equilibrium price.
Market Equilibrium
សរត្តទីផ្ារ
• Excess demand (Shortage) the amount by
which quantity demanded exceeds quantity
supplied when the price of a good lies below the
equilibrium price.
Market Equilibrium
សរត្តទីផ្ារ
• Price ceiling a maximum allowable price,
specified by law.
Determinants of Supply
ក្សត្តាជៈឥទធពិ លការផ្គតផ្់ ងគ ់
Determinants of Supply: Factors That Shift the Supply Curve
Determinant
Examples
Change in resource prices
A decrease in the price of microchips increases the
supply of computers; an increase in the price of crude
oil reduces the supply of gasoline.
Change in technology
The development of more effective wireless
technology increases the supply of cell phones.
Change in taxes and subsidies
An increase in the excise tax on cigarettes reduces the
supply of cigarettes; a decline in subsidies to state
universities reduces the supply of higher education.
26
Determinants of Supply (Con’t)
ក្សត្តាជៈឥទធិពលការផ្គតផ្់ ងគ ់
Determinants of Supply: Factors That Shift the Supply Curve
Determinant
Examples
Change in prices of other goods
An increase in the price of cucumbers decreases the
supply of watermelons.
Change in producer expectations
An expectation of a substantial rise in future log prices
decreases the supply of logs today.
Change in the number of suppliers
An increase in the number of tattoo parlors increases
the supply of tattoos; the formation of women’s
professional basketball leagues increases the supply
of women’s professional basketball games.
27
Recap (សគងេប)
• What is the Market?
• Demand?
– Schedule/curve
– Individual demand
– Market demand
– Demand equation
– Law of demand
Recap (សគងេប)
• Supply?
– Supply schedule/curve
– Individual supply
– Market supply
– Supply equation
– Law of supply
Recap (សគងេប)
• Market Equilibrium
– Surplus (Exceed Supply) creates price floor.
– Shortage (Exceed Demand) creates price
celling.
– Equilibrium conditions (ល័ក្សេសណឌ សរត្ត)
• Qd = Qs
• Pd = Ps
Exercise 1
If the supply and demand curves for a market are
given by P= 4 + 4Qs and P = 16 - 2Qd,
respectively, find the equilibrium price and quantity
for this market.
Exercise 2
Find the equilibrium price and quantity in a market
whose supply and demand curves are given by
P=2Qs and P = 8 - 2Qd, respectively.
Exercise 3
We assume:
– Qs = 1, 800 + 240p
– Qd = 3,550 - 226p
a) Draw a graph when p = $2 & p = $4
b) Calculate the market equilibrium
Exercise 4
We now have equations for supply and
demand
Supply: Qs = –4.5 + 16p
Demand: Qd = 13.5 – 8p
a) Find the market equilibrium
b) Find the market surplus, if price (p=1$)
c) Find the market shortage, if price
(p=.50$)
Appendix
• Quantity demanded: The amount of any good, service,
or resource that people are willing and able to buy during
a specified period at a specified price.
• Demand: The relationship between the quantity
demanded and the price of a good when all other
influences on buying plans remain the same.
• Demand schedule: A list of the quantities demanded at
each different price when all the other influences on
buying plans remain the same.
• Demand curve: A graph of the relationship between the
quantity demanded of a good and its price when all the
other influences on buying plans remain the same.
Key Terms (ពាក្សយគន្ឹះល )
• Demand (រម្តូវការ)
• Demand curve (ដសសគកាងតម្រូវការ)
• Demand schedule (ត្តរាងតម្រូវ
ការ)
• Quantity demand (បរិមាណតម្រូវ
ការ)
• Price (នល្ឫតនរ្)
• Buy (ទិញ)/Buyer (អ្នក្សទិញ)
• Sell (លក្ស់)/ Seller (អ្នក្សលក្ស់)
• Equal (គសមើរោន )
• Figure (រូបភាព)
• Relationship between (ទំនាក្ស់
ទំនងរវាង)
• Plan (គំរាងឫដផ្នការ)
• Influence (ជឹះឥទធិពល)
• The amount of (ច្បំនួន)
• Exceeds (គម្ច្បើនជាង/គលើស)
• Purchase (ទិញ)
Key Terms (ពាក្សយគន្ឹះល )
• Specified period (អ្ំឡុងគពលជាក្ស់
លាក្ស់)
• willing and able to (ឆនទៈឫបំណង​
និងលទធភាព)
• Remain (រក្សា)
• Equation (សរីការ)
• Market equilibrium (សរត្តទី
ផ្ារ)
• Surplus (ភាពគលើស)
• Shortage (ភាពសវឹះ)
• Graph (គូស/រូបភាព)
•
•
•
•
•
Draw (គូរ/គូស)
Supply (ផ្គត់ផ្គង់)
Supply schedule (ត្តរាងការផ្ាត់ផ្ាង់)
Supply curve (ដសសគកាងការផ្គត់ផ្ងគ ់)
Supply equation (សរីការការផ្គត់
ផ្គង់)
• Occurs (គក្សើតគឡើង)
• Rise (គឡើង)/Fall (ច្បឹះ)
Key Terms (ពាក្សយគន្ឹះល )
•
•
•
•
•
•
Increase () (គក្សើនគឡើង)
Decrease () (ធ្ល្ក្ស់ច្បឹះ)
Price ceiling (តនរ្ពិដាន)
Change in (ផ្ល្ស់បាូរ/បំដរបម្រួល)
Substitute goods (ទំនិញជំនួស)
Complement goods (ទំនិញ
បំគពញ)
• Consumption (ការគម្បើម្ាស់)
•
•
•
•
•
•
Rightward shift (ផ្ល្ស់ទីគៅស្ា ំ)
Leftward shift (ផ្ល្ស់ទីគៅគឆវង)
Interaction between (អ្នារក្សរម)
Discover (របក្សគំគ ើញ/ឲ្យគក្សើតមានគឡើង)
is defined as (ឲ្យនិយរន័យជា)
Show (បង្ហាញ)
References
• Bade, R., & Parkin, M. (2013). Essential Foundations of
Economics (6th ed.).
• Brue, S. L., McConnell, C., Flynn, S. M., & Grant, R. R.
(2010). (3rd ed.): McGraw-Hill/Irwin.
• Case, K. E., Fair, R. C., & Oster, S. M. (2012). Principles
of Economics (10th ed.): Prince Hall-Pearson
Education,.
• Frank, R. H., & Bernanke, B. S. (2009). Principles of
Microeconomics (4th ed.): McGraw Hill.
• Mateer, D., Coppock, L., & Brian, O. R. (2016).
Essentials of Economics: W.W Norton & Company, Inc.