Goal
maximize satisfaction
Limitations / Constraints
Limited
Time
Money
Budget Constraint
What you can afford due to
Price
Income
Example
Max
Income
$100
He like to
Go to movies
Cost $10 each
Go to concerts
Costs $20 Each
Graph
<html><img src="budget constraint.JPG">
Slope
change y / change x
Change movie / change concerts
Relative Price
P Concerts / Price movies
Change Income
Decrease
Shifts budget line
Right
Graph
<html><img src="changes in budget.JPG">
Increasing Income
Shifts Budget line
Right
Slope
Unchanged
Preferences
People are Rational
They have
Preferences
Consistancy / Transitivity
Options
A+B
A is better than B
B is better than A
A and B are Indifferent
A,B,C
A is better than B
B is better than C
Then A is better than C
Indifference Curve
Shows where max will be just as happy doing a certain ammount of both options
Maximun movies max is willing to trade for a concert
AKA
Marginal Rate of Substitution
Graph
<html><img src="indifference curve.JPG">
Marginal rate of Subsittution
The Slope of the tangent line
Move right allong IC
MRS
Decreases
Graph
<html><img src="indifference map.JPG">
=MRS Y1x
(Px)/(Py)
This is Price ratio
Common IC Graph Mistakes
Sloping Back up \_/
MRS Intersecting
\/
So what will his choice be
Graph
<html><img src="his choice.JPG">
He will use both
Indifference Curve
Marginal Rate of Substitution
Looking at the MRS that is tangent to IC
He will make the optimum choice
All choices have same
Price Ratio
Higher line
Better choice
This will be picked
EX
MRS Y1X
1=
(px/py) = 2
Px = 2
Py = 1
This means
Can trade
1 unit of x
for 2 units of y
Therefore
mrs = 1
Optimumly happy
px/py=1/2
px = 1
py= 2
This means
Can trade
1 unit of y
for 2 units of x
Therefore
MRS = 1
Optimumly happy
Increased income
What happens
Graph
<html><img src="increase income.JPG">
Normal and Inferior goods
Graph
<html><img src="normal and inferior.JPG">
X is Normal
Do more of x
Y is Inferrior
Do less of y
Change in Price
Graph
<html><img src="change in price of good.JPG">
Will demand more of one good
Look at Movies versus Concerts
Price =
20
# of Concerts Demanded
3
10
# of Concerts Demanded
5
5
# of Concerts Demanded
8
Connect these numbers on x,y axis
x =
Number of concerts
y =
Price of Concerts
Results in Demand Curve
Two Effects from change in P
1
Substitution Effect
Price of Concerts
Goes Down
Concerts
Cheaper than movies
Price concerts / Price Movies
Goes down
Substitute
Concerts
from Movies
Quantity Demanded Goes up
Change in Price
2
Income Effect
Raised income
Similar to Drop in Price
Concerts
Normal Good
Quantity Demanded
Rises
Inferior Good
Quantity Demanded
Drops
Occurs in Both Changes
Normal Goods
Price Drops
Sub Effect
Quantity Demanded
Rises
Income
Quantity Demanded
Rises
Both Occur
Quantity Demanded
Almost Always
Rises
Price Rises
Sub Effect
Quantity Demanded
Drops
Income
Quantity Demanded
Drops
Both Occur
Quantity Demanded
Almost Always
Drops
Inferior Goods
Price Drops
Sub Effect
Quantity Demanded
Rises
Income
Quantity Demanded
Drops
Both Occur
Quantity Demanded
Almost Always
Drops
Price Rises
Sub Effect
Quantity Demanded
Drops
Income
Quantity Demanded
Rises
Both Occur
Quantity Demanded
Almost Always
Drops
Market Demand Curve
Graph
<html><img src="from individual to market demand.JPG">
First see how much each person will buy
Take those values
add together
Place them all on a graph
Connect
Topic
Extensions
Reality of Indifference Curves
There are really more good than just 2
Not only movies and Concerts
He could watch sports
Lending and Borrowing
Could borrow
Go to more more movies + concerts
Lend
Dont have to spend all money on goods
could save
Uncertainty + Information
Will the concerts Be good?
I need more infor
Buy a CD
Less money for concerts + movies
Altruism
"Satisfaction of others"
Give money to charity
Behavioral Economics
Salience
Credit card companies hiding info in contracts
Preference for Default
Choose what is offered
Default opt in for email
Decision making environment
If i make tables close to ice cream
People will buy ice cream'
Self Binding
PAy to make it illegal to gamble