Bahan Kuliah Ek. Mikro Choices Made by Household and Firm 0

Ekonom ika M ikr o
( PEK 411)
1

CH O I CE S M A D E B Y
H O U SE H O L D S A N D F I R M S
Losina Purnastuti, M .Ec.Dev. Ph.D

PEN D I D I K AN EK ON OM I
FE - UN Y
2 0 12

Fir m and H ousehold D ecisions

H ousehold Behavior and Consum er Choice
 H ousehold Choice in

Output M ar kets
 The Basis of Choice:
U tility
 I ncom e and

Substitution Effects
 The I ndiffer ence
Cur ve Appr oach

The D eter m inants of H ousehold D em and
 The price of the product
 The incom e available to the household
 The household's amount of accumulated wealth
 The prices of other products available to the

household
 The household's tastes and preferences
 The household's expectations about future income,
wealth, and prices

The Budget Constr aint

 A consumer’s budget constraint identifies which

combinations of goods and service the consumer can

afford with a limited budget, at given prices.
 Budget constraint: The different combinations of
good a consumer can afford with a limited budget, at
given price.

The Budget Constr aint… cont

The Equation of the Budget Constr aint

Changes in The Budget Line
 Change in I ncome
 Change in Price

Changes in The Budget Line... cont

Consumer Decision: The Marginal Utility Approach

Consumer Decision: The Marginal Utility Approach... cont
 M ar ginal U tility ( M U ) : The a dditiona l


satisfaction gained by the consum ption or use of
one m or e unit of a good or ser vice.
 Total U tility ( TU ) : The total am ount of

satisfaction obtained fr om consum ption of a
good or ser vice.
 Law of D im inishing M ar ginal U tility: The m or e

of any one good consum ed in a given per iod, the
less satisfaction ( utility) gener ated by
consum ing each additional ( m ar ginal) unit of the
sam e good.

Allocating I ncom e to M axim ize U tility

Allocating I ncom e to M axim ize U tility... cont

Deriving the Demand Curve

I NCOME AND SUBSTI TUTI ON EFFECTS

 “Great news! Now that Pepsi

is cheaper, my income has
greater purchasing power. I
am, in effect, richer than I
was. Because I am richer, I
can buy both more Pepsi and
more pizza.” (This is the
income effect.)

 “Now that the price of Pepsi

has fallen, I get more pints of
Pepsi for every pizza that I
give up. Because pizza is now
relatively more expensive, I
should buy less pizza and
more Pepsi.” (This is the
substitution effect.)


I NCOME AND SUBSTI TUTI ON EFFECTS... cont

The I ndifference Curve Approach
 NEXT MEETI NG

ASSU M PTI ON S
 We assume that this analysis is restricted to goods that yield

positive marginal utility, or, more simply, that "more is better.”

 The m ar ginal r ate of substitution is defined as MUX/ MUY,

or the ratio at which a household is willing to substitute X for Y.

 We assume that consumers have the ability to choose among the

combinations of goods and services available.

 We assume that consumer choices are consistent with a simple


assumption of rationality. I f a consumer shows that he prefers A to
B a nd subsequently show s tha t he prefers B to a thir d
a lter na tive, C, he should pr efer A to C when confronted with
a choice between the two.

D ERI VI N G I N D I F F E R E N C E CU RVES

The Marginal Rate of Substitution

Consumer Decision Making

What Happen When Things Change?

Deriving the Demand Curve

I NCOME AND SUBSTI TUTI ON EFFECTS
 “Great news! Now that Pepsi

 “Now that the price of Pepsi


is cheaper, my income has
greater purchasing power. I
am, in effect, richer than I
was. Because I am richer, I
can buy both more Pepsi and
more pizza.” (This is the
income effect.)
 income effect: the change in
consumption that r esults
when a pr ice change moves
the consumer to a higher or
lower indiffer ence cur ve

has fallen, I get more pints of
Pepsi for every pizza that I
give up. Because pizza is now
relatively more expensive, I
should buy less pizza and
more Pepsi.” (This is the
substitution effect.)

 substitution effect: the change
in consumption that r esults
when a pr ice change moves
the consumer along a given
indiffer ence cur ve to a point
with a new mar ginal r ate of
substitution

I ncom e and Substitution Effects W hen the Pr ice of Pepsi Falls

I NCOME AND SUBSTI TUTI ON EFFECTS... cont

A Giffen Good
A GIFFEN GOOD.
In this example, when
the price of potatoes
rises, the consumer’s
optimum shifts from
point C to point E. In
this case, the

consumer responds
to a higher price of
potatoes by buying
less meat and more
potatoes.