Download SSEMI2: Law of Demand, Law of Supply

» As prices rise, the quantity demanded of a good or
service will fall
˃ People buy less stuff when the price goes up!
Q
D
P
u
e
r
a
m
i
n
a
c
t
n
e
i
˃ Or:
d
s
t
y
˃ As prices FALL, the quantity demanded of a good or service will RISE
Q
D
P
u
e
r
a
m
i
n
a
c
t
n
e
i
d
s
t
y
» Example: Ms. Yeomans needs some pencils for
school
˃ At Walmart, she finds a box of 12 pencils is $1
$1
˃ This is such a great price she decides to buy 5 boxes!
˃ As she is going to the register she sees that all office supplies are on sale!!!
˃ This is great! She hurries back to grab 3 more boxes!
˃ Why did she buy more?
» As the price a seller can charge for their good or
service rises, the quantity supplied will increase
P
r
i
c
e
s
Q
u
S
a
u
n
p
t
p
i
l
t
y
y
» Example:
˃ Cardinal Diner makes and sells gingerbread cookies
˃ It costs them 10¢ to make the cookies so they have to charge at least
10¢ for them.
˃ They don’t make any money at this price though so they don’t make
very many cookies.
˃ If they can charge 20¢ per cookie they will make 100 cookies to sell
˃ If they can charge 30¢ per cookie they will make 200 cookies to sell
˃ Why do they make more?
» How do we know what price will eventually be
charged?
˃ We use a Supply schedule and a Demand schedule
+ A list of quantity supplied and quantity demand at a range of
prices
» Example:
˃ Chicken sandwiches
+ At $1 consumers will demand
43 chicken sandwiches but
producers will only supply 1
Quantity
Supplied
Price
Quantity
Demand
49
$7
4
39
$6
8
29
$5
13
19
$4
19
12
$3
26
5
$2
34
1
$1
43