perilaku konsumen ii 2 bs w5

KURVA INDIFFERENCE II

Copyright©2004 South-Western

Review Pertemuan Sebelumnya







Budget Constraint / Kendala Anggaran
Prefences
Indifference Curve
4 Sifat Kurva Indifference
Marginal Rate of Substitution (MRS)
Optimalisasi Pilihan Konsumen

Copyright©2004 South-Western


Review: Budget Constraint
• The budget constraint shows the various
combinations of goods the consumer can afford
given his or her income and the prices of the
two goods.
• The limit on the consumption “bundles” that a
consumer can afford.
• People consume less than they desire because
their spending is constrained, or limited, by
their income
Copyright©2004 South-Western

Review: Budget Constraint
Ice
Cream
(cup)

Pengeluaran
utk
Ice Cream


Coklat
(Batang)

Pengeluaran
utk
Coklat

Pengeluaran
Total

0

100

0

1000

1000


50

90

100

900

1000

100

80

200

800

1000


150

70

300

700

1000

200

60

400

600

1000


250

50

500

500

1000

300

40

600

400

1000


350

30

700

300

1000

400

20

800

200

1000


450

10

900

100

1000

500

0

1000

0

1000

Copyright©2004 South-Western

Review: Budget Constraint
Quantity of Ice
Cream
500

B

Consumer’s
budget constraint

0

A
100

Quantity of Coklat
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Review: Budget Constraint
Quantity
of Ice Cream
500

250

B

C
Consumer’s
budget constraint

A
0

50

100


Quantity
of Coklat

Copyright©2004 South-Western

Review: Preferences
• Secara sederhana preferences adalah apa-apa
yang diinginkan konsumen.
• Sekumpulan (bundle) barang & jasa yang
diinginkan konsumen
• Setiap orang memiliki preferensi yang berbedabeda

Copyright©2004 South-Western

Review: Kurva Indifference
• Preference atau preferensi seseorang bisa
ditunjukkan dengan kurva indifference
• Kurva Indifference adalah kurva yg
menunjukkan kumpulan/kelompok/kombinasi
konsumsi dimana konsumen memiliki tingkat

utilitas / kepuasan yg sama (indifference).

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Review: Kurva Indifference
Quantity
of
Ice Cream

C

B

D
I2
A

0

Indifference
curve, I1
Quantity
of Coklat
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Review: 4 Sifat Kurva Indifference
• Kurva Indifference yg lebih tinggi lebi disukai
daripada yg lebih rendah.
• Kurva Indifference berbentuk miring dari kiri
atas ke kanan bawah.
• Kurva Indifference tidak saling berpotongan
satu sama lain.
• Kurva Indifference cembung terhadap titik 0
(titik origin).
Copyright©2004 South-Western

Review: The Marginal Rate of
Substitution (MRS)
• The Marginal Rate of Substitution ditunjukkan
oleh slope Kurva Indifference
• Adalah tingkat dimana konsumen bersedia
menukarkan satu barang untuk barang yg lain.
• Jumlah barang yg harus diberikan agar
sesorang bersedia mengurangi konsumsi barang
yg lain.

Copyright©2004 South-Western

Review: The Marginal Rate of Substitution (MRS)
Quantity
of
Ice Cream

C

B
MRS

D
I2

1
A

0

Indifference
curve, I1
Quantity
of Coklat
Copyright©2004 South-Western

Review: The Marginal Rate of Substitution (MRS)
Quantity
of
Ice Cream
14
MRS = 6
A

8

1

4
3

0

B

MRS = 1
1

2

3

6

Indifference
curve
7

Quantity
of Coklat
Copyright©2004 South-Western

Review: Optimalisasi Pilihan Konsumen
• Combining the indifference curve and the
budget constraint determines the consumer’s
optimal choice.
• Consumer optimum occurs at the point where
the highest indifference curve and the budget
constraint are tangent.

Copyright©2004 South-Western

Review: Optimalisasi Pilihan Konsumen
Quantity
of
Ice Cream
Optimum
B

A
I3
I1

I2

Budget constraint
0

Quantity
of Coklat
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Perubahan
Keseimbangan Konsumen
1. Perubahan Budget / Income
1. Perubahan Harga Barang

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1. Perubahan Budget / Income
• Perubahan Income konsumen akan menggeser budget
constraint dengan arah sejajar
• Kenaikan income akan menggeser budget constraint ke
luar / kanan
• Konsumen memiliki kemampuan untuk memilih kombinasi
barang dan jasa pada kurva indifference yg lebih tinggi.

• Penurunan income akan menggeser budget constraint
ke dalam / kiri
• Konsumen harus memilih kombinasi brg/jasa pada kurva
indifference yg lebih rendah

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1. Perubahan Income  Peningkatan Income
Quantity
of
Ice Cream

New budget constraint

1. An increase in income shifts the
budget constraint outward . . .
New optimum
3. . . .Konsumsi
Ice Cream Naik

Initial
optimum

Initial
budget
constraint

I2

I1

0
2. . . . konsumsi coklat naik . . .

Quantity
of Coklat

Copyright©2004 South-Western

1. Perubahan Budget / Income
• Barang Normal vs Barang Inferior
• If a consumer buys more of a good when his or her
income rises, the good is called a normal good.
• If a consumer buys less of a good when his or her
income rises, the good is called an inferior good.

Copyright©2004 South-Western

1.

Perubahan Income  Barang inferior
Quantity
of

Bakiak

New budget constraint

1. An increase in income shifts the
budget constraint outward . . .

3. . . .Konsumsi
Bakiak Turun

Initial
optimum
New optimum
Initial
budget
constraint

I1
I2

0
2. . . . konsumsi coklat naik . . .

Quantity
of Coklat

Copyright©2004 South-Western

2. Perubahan Harga Barang
• Perubahan harga barang akan merubah
kemiringan kurva indifference
• Turunnya harga barang akan membuat kurva
indifference memiliki kemiringan lebih tegak
• Demikian juga sebaliknya

Copyright©2004 South-Western

2. Perubahan Harga Barang: Harga Ice Cream Turun
Quantity
of
Ice Cream
1,000 D

New budget constraint

New optimum
500

1. A fall in the price of Pepsi rotates
the budget constraint outward . . .

B

3. . . . Konsumsi
ice cream naik

Initial optimum
Initial
budget
constraint
0

I1

I2

A
100

2. . . . Konsumsi coklat turun . . .

Quantity
of Coklat
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2. Perubahan Harga Barang
• A price change has two effects on consumption.
1. Income Effect
2. Substitution Effect

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2. Perubahan Harga Barang :
 Income and Substitution Effects
• The Income Effect
• Merupakan perubahan konsumsi ke dalam kurva
indifference yg lebih tinggi atau lebih rendah sbg
akibat perubahan harga.

• The Substitution Effect
• Merupakan perubahan konsumsi di sepanjang
kurva indifference sbg akibat perubahan harga.

Copyright©2004 South-Western

2. Perubahan Harga Barang :
 Income and Substitution Effects
• Substitution Effect
• Perubahan harga menyebabkan konsumsi konsumen
berpindah dari satu titik ke titik dilain di sepanjang
kurva indifference yg sama
• Ditunjukkan dari pergerakan dari titik A ke B.

• Income Effect
• Setelah berpindah dari satu titik ke titik lain,
konsumen kemudian pindah ke titik di kurva
indifference yg lain (lebih tinggi atau lebih rendah).
• Ditunjukkan dari pergerakan dari titik B ke C
Copyright©2004 South-Western

2. Perubahan Harga Barang :
 Income and Substitution Effects
Quantity
of
Ice Cream
New budget constraint

C New optimum
Income
effect

B

Substitution
effect

Initial
budget
constraint

Initial optimum

A

I2
I1

0

Substitution effect
Income effect

Quantity
of Coklat
Copyright©2004 South-Western

Menurunkan Kurva Permintaan
• Kurva permintaan konsumen bisa dilihat
sebagai keputusan optimal seorang konsumen
yg berasal dari interaksi antara budget
constraint dan kurva indifference konsumen
tersebut.

Copyright©2004 South-Western

Menurunkan Kurva Permintaan

(a) The Consumer’s Optimum

(b) The Demand Curve for Pepsi

Quantity
of
New budget constraint
Ice Cream

750

Price of
Ice
Creami

B

$2

A

I2

250

B

1

A

Demand

I1
0

Initial budget
constraint

Quantity
of Coklat

0

250

750

Quantity
of Ice Cream

Copyright©2004 South-Western

Giffen Goods
• Economists use the term Giffen good to
describe a good that violates the law of
demand.
• Giffen goods are goods for which an increase
in the price raises the quantity demanded.
• The income effect dominates the substitution
effect.
• They have demand curves that slope
upwards.
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