Transcript quantity supplied - Effingham County Schools

Chapter 4 Part 2
Supply
• Quantity supplied – amount of a good that
sellers are willing and able to sell
• Law of supply – the quantity supplied of a
good rises as price rises
• Supply schedule – table showing
relationship b/t the price and quantity
supplied of a good
• Supply curve – graph of relationsip b/t P
and Qs
Figure 5 Ben’s Supply Schedule and
Supply Curve
Price of
Ice-Cream
Cone
$3.00
1. An
increase
in price ...
2.50
2.00
1.50
1.00
0.50
0
1 2
3
4
5
6
7
8
9 10 11 12 Quantity of
Ice-Cream Cones
2. ... increases quantity of cones supplied.
• Market supply – the sum of all individual
suppliers in the same market
• Graphically, individual supply curves are
summed horizontally to obtain the market
supply curve
• Change in Qs - Caused by a change in
anything that alters the quantity supplied at
each price.
Change in Quantity Supplied
Price of IceCream
Cone
S
C
$3.00
A rise in the price
of ice cream
cones results in a
movement along
the supply curve.
A
1.00
0
1
5
Quantity of
Ice-Cream
Cones
Shifts in the S curve – Change in Supply
• Input Prices – when the P of an input rises,
the S decreases b/c it is more expensive to
produce and less profitable
• Technology – advances in technology can
increase the supply
• Expectations – if the firm expects prices to
rise in future, may produce less now
• # of sellers – if more firms enter market, S
will go up
Figure 7 Shifts in the Supply Curve
Price of
Ice-Cream
Cone
Supply curve, S3
Decrease
in supply
Supply
curve, S1
Supply
curve, S2
Increase
in supply
0
Quantity of
Ice-Cream Cones
S and D together
• Equilibrium refers to a situation in which
the price has reached the level where
quantity supplied equals quantity demanded
• Occurs where the S and D curve intersect
• Equilibrium Price – price at intersection
• Equilibrium Quantity – Q at intersection
Figure 8 The Equilibrium of
Supply and Demand
Price of
Ice-Cream
Cone
Supply
Equilibrium
Equilibrium price
$2.00
Equilibrium
quantity
0
1
2
3
4
5
6
7
8
Demand
9 10 11 12 13
Quantity of Ice-Cream Cones
Markets not in Equilibrium
• SURPLUS - When price > equilibrium
price, then quantity supplied > quantity
demanded.
• There is excess supply or a surplus.
• Suppliers will lower the price to increase
sales, thereby moving toward equilibrium.
Figure 9 Markets Not in
Equilibrium
(a) Excess Supply
Price of
Ice-Cream
Cone
Supply
Surplus
$2.50
2.00
Demand
0
4
Quantity
demanded
7
10
Quantity
supplied
Quantity of
Ice-Cream
Cones
Markets not in Equilibrium
• SHORTAGE -When price < equilibrium
price, then quantity demanded > 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.
Figure 9 Markets Not in
Equilibrium
(b) Excess Demand
Price of
Ice-Cream
Cone
Supply
$2.00
1.50
Shortage
Demand
0
4
Quantity
supplied
7
10
Quantity of
Quantity
Ice-Cream
demanded
Cones
Table 3: Three Steps for Analyzing
Changes in Equilibrium
Figure 10 How an Increase in Demand Affects
the
Equilibrium
Price of
Ice-Cream
Cone
1. Hot weather increases
the demand for ice cream . . .
Supply
New equilibrium
$2.50
2.00
2. . . . resulting
in a higher
price . . .
Initial
equilibrium
D
D
0
7
3. . . . and a higher
quantity sold.
10
Quantity of
Ice-Cream Cones
Figure 11 How a Decrease in Supply
Affects
the
Equilibrium
Price of
Ice-Cream
Cone
S2
1. An increase in the
price of sugar reduces
the supply of ice cream. . .
S1
New
equilibrium
$2.50
Initial equilibrium
2.00
2. . . . resulting
in a higher
price of ice
cream . . .
Demand
0
4
7
3. . . . and a lower
quantity sold.
Quantity of
Ice-Cream Cones
Table 4: What Happens to Price and
Quantity When Supply or Demand Shifts?