© 2002 Prentice Hall Business Publishing© 2002 Prentice Hall Business Publishing Principles of Economics, 6/ePrinciples of Economics, 6/e Karl Case, Ray FairKarl Case, Ray Fair

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Prepared by: INSAN HASANIPrepared by: INSAN HASANI

Permintaan, Penawaran, Permintaan, Penawaran, dan Market Equilibriumdan Market Equilibrium

PengantarPengantar

• Pasar (who, what, how)Pasar (who, what, how)

• Penawaran dan permintaan adalah suatu model ekonomiPenawaran dan permintaan adalah suatu model ekonomi

• Menjelaskan bagaimana harga ditentukan pada jenis Menjelaskan bagaimana harga ditentukan pada jenis pasar tertentupasar tertentu

• Apa yang akan dipelajari pada bahasan iniApa yang akan dipelajari pada bahasan ini

• Bagaimana model dari penawaran dan permintaan Bagaimana model dari penawaran dan permintaan bekerja dan bagaimana untuk menggunakannyabekerja dan bagaimana untuk menggunakannya

• Hukum permintaanHukum permintaan

• Hukum penawaranHukum penawaran

• Penentuan market equilibriumPenentuan market equilibrium

• Faktor-faktor yang menggerakkan kurva penawaran dan Faktor-faktor yang menggerakkan kurva penawaran dan permintaanpermintaan

PasarPasar

• Dari sudut pandang ekonomi, pasar adalah Dari sudut pandang ekonomi, pasar adalah bukan tempat tetapi merupakan kelompok dari bukan tempat tetapi merupakan kelompok dari pembeli dan penjual yang melakukan pembeli dan penjual yang melakukan pertukaran satu dengan lainnyapertukaran satu dengan lainnya

• Pasar didefinisikan bukan oleh lokasinya tetapi para Pasar didefinisikan bukan oleh lokasinya tetapi para pesertanyapesertanya

• Langkah awal dalam melakukan analisis ekonomi Langkah awal dalam melakukan analisis ekonomi adalah mengidentifikasikan jenis pasar, langkah adalah mengidentifikasikan jenis pasar, langkah berikutnya adalah mengklasifikasikannya berikutnya adalah mengklasifikasikannya

• Para ahli ekonomi berpendapat bahwa ekonomi Para ahli ekonomi berpendapat bahwa ekonomi merupakan kumpulan dari berbagai pasarmerupakan kumpulan dari berbagai pasar

Seberapa luas definisi dari pasarSeberapa luas definisi dari pasar

• Hal yang dipertimbangkan dari pasar menurut Hal yang dipertimbangkan dari pasar menurut ahli ekonomi adalahahli ekonomi adalah

• AggregationAggregation yaitu kombinasi dari satu kelompok dari yaitu kombinasi dari satu kelompok dari hal yang terpisah kedalam satu kesatuanhal yang terpisah kedalam satu kesatuan

• Seberapa luas dan terbatasnya definisi dari Seberapa luas dan terbatasnya definisi dari pasar tergantung pada tujuan, hal penting yang pasar tergantung pada tujuan, hal penting yang membedakan adalah secara membedakan adalah secara MacroeconomicsMacroeconomics dan dan MicroeconomicsMicroeconomics

Definisi Pasar (Definisi Pasar (MacroMacroeconomic)economic)

• Barang dan jasa dikumpulkan pada tingkat yang Barang dan jasa dikumpulkan pada tingkat yang paling tinggipaling tinggi

• Model makro mengumpulkan seluruh barang Model makro mengumpulkan seluruh barang konsumen kedalam satu kategori yaitu “konsumen kedalam satu kategori yaitu “consumption consumption goodsgoods””

• Model makro juga menganalisis seluruh barang Model makro juga menganalisis seluruh barang modal sebagai satu pasarmodal sebagai satu pasar

• Sudut pandang para ahli makroekonomi tentang Sudut pandang para ahli makroekonomi tentang ekonomi adalah secara umum tidak detailekonomi adalah secara umum tidak detail

Definisi Pasar (Definisi Pasar (MicroMicroeconomic)economic)

• Pasar didefinisikan lebih terbatasPasar didefinisikan lebih terbatas

• Fokus dari model menggambarkan komoditas yang Fokus dari model menggambarkan komoditas yang lebih spesifiklebih spesifik

• Selalu melibatkan beberapa Selalu melibatkan beberapa aggregationaggregation

• Namun berhenti pada saat mencapai tingkatan yang Namun berhenti pada saat mencapai tingkatan yang paling tinggi dari kondisi umum berdasarkan sudut paling tinggi dari kondisi umum berdasarkan sudut pandang makroekonomipandang makroekonomi

Pembeli dan PenjualPembeli dan Penjual

• Pembeli dan penjual didalam satu pasar yaitu:Pembeli dan penjual didalam satu pasar yaitu:

• Rumah tanggaRumah tangga

• PerusahaanPerusahaan

• Agen pemerintahAgen pemerintah• Seluruhnya dapat bertindak sebagai pembeli ataupun Seluruhnya dapat bertindak sebagai pembeli ataupun

penjual pada pasar yang sama, namun tidak selalupenjual pada pasar yang sama, namun tidak selalu

• Untuk tujuan penyederhanaan makaUntuk tujuan penyederhanaan maka

• Pada pasar barang konsumen, perusahaan sebagai Pada pasar barang konsumen, perusahaan sebagai pejual, dan rumah tangga sebagai pembelipejual, dan rumah tangga sebagai pembeli

• Untuk sementara, “perantara” tidak dibahasUntuk sementara, “perantara” tidak dibahas

Unit Penentu KeputusanUnit Penentu Keputusan

• PerusahaanPerusahaan adalah suatu organisasi yang adalah suatu organisasi yang merubah merubah resources (inputs) resources (inputs) kebentuk kebentuk products products (outputs)(outputs). Perusahaan adalah unit yang . Perusahaan adalah unit yang berproduksi didalam ekonomi pasar.berproduksi didalam ekonomi pasar.

• EntrepreneurEntrepreneur adalah orang yang adalah orang yang mengorganisir, mengatur, dan mengorganisir, mengatur, dan mengasumsikan resiko dari suatu perusahaan, mengasumsikan resiko dari suatu perusahaan, memiliki ide baru terhadap suatu produk dan memiliki ide baru terhadap suatu produk dan terlibat pada kesuksesan suatu bisnisterlibat pada kesuksesan suatu bisnis

• Rumah tanggaRumah tangga adalah unit yang bertindak adalah unit yang bertindak sebagai konsumen didalam ekonomi pasar.sebagai konsumen didalam ekonomi pasar.

The Circular Flow of Economic ActivityThe Circular Flow of Economic Activity

• The The circular flow of circular flow of economic activityeconomic activity shows shows the connections between the connections between firms and households in firms and households in input and output markets.input and output markets.

Input Markets and Output MarketsInput Markets and Output Markets

• Output, or product, Output, or product, marketsmarkets are the markets are the markets in which goods and in which goods and services are exchanged.services are exchanged.

• Input marketsInput markets are the are the markets in which markets in which resources—labor, capital, resources—labor, capital, and land—used to and land—used to produce products, are produce products, are exchanged.exchanged.

• Payments flow in the opposite Payments flow in the opposite direction as the physical flow of direction as the physical flow of resources, goods, and services resources, goods, and services (counterclockwise).(counterclockwise).

Input MarketsInput Markets

Input markets include:Input markets include:

• The The labor marketlabor market, in which households supply , in which households supply work for wages to firms that demand labor.work for wages to firms that demand labor.

• The The capital marketcapital market, in which households supply , in which households supply their savings, for interest or for claims to future their savings, for interest or for claims to future profits, to firms that demand funds to buy capital profits, to firms that demand funds to buy capital goods.goods.

• The The land marketland market, in which households supply , in which households supply land or other real property in exchange for rent.land or other real property in exchange for rent.

Determinants of Household DemandDeterminants of Household Demand

• The The price of the productprice of the product in question. in question.

• The The incomeincome available to the household. available to the household.

• The household’s amount of The household’s amount of accumulated wealthaccumulated wealth..

• The The prices of related productsprices of related products available to the available to the household.household.

• The household’s The household’s tastes and preferencestastes and preferences..

• The household’s The household’s expectationsexpectations about future about future income, wealth, and prices.income, wealth, and prices.

A household’s decision about the quantity of a particular A household’s decision about the quantity of a particular output to demand depends on:output to demand depends on:

Quantity DemandedQuantity Demanded

• Quantity demandedQuantity demanded is the amount is the amount (number of units) of a product that a (number of units) of a product that a household would buy in a given time household would buy in a given time period if it could buy all it wanted at period if it could buy all it wanted at the current market price.the current market price.

Jenis PermintaanJenis Permintaan

• Permintaan Absurd/AbsolutPermintaan Absurd/Absolut

Permintaan yang tidak diikuti dengan kemampuan untuk membeliPermintaan yang tidak diikuti dengan kemampuan untuk membeli

• Permintaan PotensialPermintaan Potensial

Permintaan yang sudah didukung oleh daya beli, namun belum terdapat keinginan Permintaan yang sudah didukung oleh daya beli, namun belum terdapat keinginan untuk membeli. untuk membeli.

• Permintaan EfektifPermintaan Efektif

Permintaan yang didukung oleh kemampuan untuk membeli Permintaan yang didukung oleh kemampuan untuk membeli

(mempunyai daya beli)(mempunyai daya beli)

• Permintaan IndividuPermintaan Individu

Permintaan yang dilakukan oleh satu konsumen sajaPermintaan yang dilakukan oleh satu konsumen saja

• Permintaan PasarPermintaan Pasar

Permintaan yang dilakukan oleh konsumen secara keseluruhan dalam pasarPermintaan yang dilakukan oleh konsumen secara keseluruhan dalam pasar..

Demand in Output MarketsDemand in Output Markets

• A A demand scheduledemand schedule is a table showing is a table showing how much of a given how much of a given product a household product a household would be willing to would be willing to buy at different prices.buy at different prices.

• Demand curves are Demand curves are usually derived from usually derived from demand schedules.demand schedules.

PRICE (PER

CALL)

QUANTITY DEMANDED (CALLS PER

MONTH)$ 0 30

0.50 253.50 77.00 3

10.00 115.00 0

ANNA'S DEMAND SCHEDULE FOR

TELEPHONE CALLS

The Demand CurveThe Demand Curve

• The The demand curvedemand curve is is a graph illustrating a graph illustrating how much of a given how much of a given product a household product a household would be willing to would be willing to buy at different prices.buy at different prices.

PRICE (PER

CALL)

QUANTITY DEMANDED (CALLS PER

MONTH)$ 0 30

0.50 253.50 77.00 3

10.00 115.00 0

ANNA'S DEMAND SCHEDULE FOR

TELEPHONE CALLS

The Law of DemandThe Law of Demand

• The The law of demandlaw of demand states that there is a states that there is a negative, or inverse, negative, or inverse, relationship between relationship between price and the quantity price and the quantity of a good demanded of a good demanded and its price.and its price.

• This means that This means that demand curves slope demand curves slope downward.downward.

HUKUM PERMINTAANHUKUM PERMINTAAN

Apabila harga suatu barang naik, permintaan Apabila harga suatu barang naik, permintaan barang tersebut akan turun. Jika harga suatu barang tersebut akan turun. Jika harga suatu barang turun, maka permintaan barang tersebut barang turun, maka permintaan barang tersebut akan naik,akan naik,

ceteris paribus..

Ceteris paribusCeteris paribus

Hukum permintaan ini hanya akan berlaku Hukum permintaan ini hanya akan berlaku apabila asumsi faktor-faktor lainnya selain apabila asumsi faktor-faktor lainnya selain harga barang tersebut dianggap tetap terpenuhi harga barang tersebut dianggap tetap terpenuhi atau tidak berubah, yaitu:atau tidak berubah, yaitu:

a. Harga barang substitusi/komplementer,a. Harga barang substitusi/komplementer,

b. Pendapatan masyarakat,b. Pendapatan masyarakat,

c. Selera masyarakat,c. Selera masyarakat,

d. Ramalan harga di masa datang,d. Ramalan harga di masa datang,

e. Jumlah penduduk. e. Jumlah penduduk.

Other Properties of Demand CurvesOther Properties of Demand Curves

• Demand curves intersect the Demand curves intersect the quantity (quantity (XX)-axis, as a result of )-axis, as a result of time limitations and diminishing time limitations and diminishing marginal utility.marginal utility.

• Demand curves intersect the Demand curves intersect the ((YY)-axis, as a result of limited )-axis, as a result of limited incomes and wealth.incomes and wealth.

Income and WealthIncome and Wealth

• IncomeIncome is the sum of all households is the sum of all households wages, salaries, profits, interest wages, salaries, profits, interest payments, rents, and other forms of payments, rents, and other forms of earnings in a given period of time. It is earnings in a given period of time. It is a a flowflow measure. measure.

• WealthWealth, or , or net worthnet worth, is the total value , is the total value of what a household owns minus what of what a household owns minus what it owesit owes.. It is a It is a stockstock measure. measure.

Related Goods and ServicesRelated Goods and Services

• Normal GoodsNormal Goods are goods for which are goods for which demand goes up when income is demand goes up when income is higher and for which demand goes higher and for which demand goes down when income is lower.down when income is lower.

• Inferior Goods are goods for which demand falls when income rises.

Contoh: Inferior GoodsContoh: Inferior Goods

Salah satu contoh barang inferior adalah Salah satu contoh barang inferior adalah Sandal JepitSandal Jepit. .

Ketika tingkat Ketika tingkat pendapatanpendapatan masyarakat rendah, tingkat permintaan masyarakat rendah, tingkat permintaan terhadap barang tersebut akan tinggi. Namun ketika tingkat pendapat terhadap barang tersebut akan tinggi. Namun ketika tingkat pendapat masyarakat meningkat, permintaan atas barang tersebut akan turun masyarakat meningkat, permintaan atas barang tersebut akan turun karena masyarakat meninggalkannya dan memilih untuk membeli karena masyarakat meninggalkannya dan memilih untuk membeli sandal lain yang lebih berkualitas meskipun dengan harga yang lebih sandal lain yang lebih berkualitas meskipun dengan harga yang lebih mahal.mahal.

Related Goods and ServicesRelated Goods and Services

• SubstitutesSubstitutes are goods that can serve as are goods that can serve as replacements for one another; when the replacements for one another; when the price of one increases, demand for the price of one increases, demand for the other goes up. other goes up. Perfect substitutesPerfect substitutes are are identical products.identical products.

• Complements are goods that “go together”; a decrease in the price of one results in an increase in demand for the other, and vice versa.

Contoh: Substitutes and Complements GoodsContoh: Substitutes and Complements Goods

• Contoh barang substitusi adalah Pepsi dan Contoh barang substitusi adalah Pepsi dan Coca-Cola, atau Xenia dan AvanzaCoca-Cola, atau Xenia dan Avanza ..

• Contoh klasik barang komplemen adalah rokok dan kopi, kacang dan bir, dan junk food dan minuman bersoda .

Example: The Demand CurveExample: The Demand Curve

Number of Bottles per Month

Price per Bottle

A

B

$4.00

2.00

D

40,000 60,000

At $2.00 per bottle, 60,000 bottles are demanded (point B).

When the price is $4.00 per bottle, 40,000 bottles are demanded (point A).

““Shifts” vs. “Movements Along” The Shifts” vs. “Movements Along” The Demand CurveDemand Curve

• Move along the demand curveMove along the demand curve

• From a change in the From a change in the priceprice of the good we of the good we analyzeanalyze

• In maple syrup example, Figure 1In maple syrup example, Figure 1

• A fall in price would cause a movement to the right along the A fall in price would cause a movement to the right along the demand curve (point A to B)demand curve (point A to B)

• See figure 3(a)See figure 3(a)

Figure 3(a): Movements Along and Figure 3(a): Movements Along and Shifts of The Demand CurveShifts of The Demand Curve

Quantity

Price

P2

Q2 Q1 Q3

P1

P3

Price increase moves us leftward along demand curve

Price decrease moves us rightward along demand curve

““Shifts” vs. “Movements Along” The Shifts” vs. “Movements Along” The Demand CurveDemand Curve

• Shift of demand curveShift of demand curve

• a change in other things than price of the good a change in other things than price of the good causes a shift in the demand curve itself, for causes a shift in the demand curve itself, for example, incomeexample, income

• In Figure 2In Figure 2

• Demand curve has shifted to the right of the old Demand curve has shifted to the right of the old curve (from Figure 1) as income has risencurve (from Figure 1) as income has risen

• A change in any variable that affects demand—A change in any variable that affects demand—except for the good’s price—causes the demand except for the good’s price—causes the demand curve to shiftcurve to shift

Figure 2: A Shift of The Demand Figure 2: A Shift of The Demand CurveCurve

B C$2.00

60,000 80,000

D1D2

An increase in income shifts the demand curve for maple syrup from D1 to D2.

Number of Bottles per Month

Price per Bottle

At each price, more bottles are demanded after the shift

““Change in Quantity Demanded” vs. Change in Quantity Demanded” vs. “Change in Demand”“Change in Demand”

• Language is important when discussing demandLanguage is important when discussing demand

• ““Quantity demanded” meansQuantity demanded” means

• A particular amount that buyers would choose to buy at a A particular amount that buyers would choose to buy at a specific pricespecific price

• It is a number represented by a It is a number represented by a single pointsingle point on a demand on a demand curvecurve

• When a change in the price of a good moves us along a When a change in the price of a good moves us along a demand curve, it is a change in quantity demanddemand curve, it is a change in quantity demand

• The term demand meansThe term demand means

• The entire relationship between price and quantity The entire relationship between price and quantity demandeddemanded——and represented by the and represented by the entire demand curveentire demand curve

• When something other than price changes, causing the When something other than price changes, causing the entire demand curve to shift, it is a change in demandentire demand curve to shift, it is a change in demand

Income: Factors That Shift The Income: Factors That Shift The Demand CurveDemand Curve

• An increase in income has effect of shifting An increase in income has effect of shifting demand for normal goods to the rightdemand for normal goods to the right

• However, a rise in income shifts demand for inferior However, a rise in income shifts demand for inferior goods to the leftgoods to the left

• A rise in income will increase the demand for a A rise in income will increase the demand for a normal good, and decrease the demand for an normal good, and decrease the demand for an inferior goodinferior good

• Normal good and inferior good are defined by Normal good and inferior good are defined by the relation between demand and incomethe relation between demand and income

Wealth: Factors That Shift The Wealth: Factors That Shift The Demand CurveDemand Curve

• Your wealth—at any point in time—is the total Your wealth—at any point in time—is the total value of everything you own minus the total value of everything you own minus the total dollar amount you owedollar amount you owe

- Example- Example

• An increase in wealth willAn increase in wealth will

• Increase demand (shift the curve rightward) for a Increase demand (shift the curve rightward) for a normal goodnormal good

• Decrease demand (shift the curve leftward) for an Decrease demand (shift the curve leftward) for an inferior goodinferior good

Prices of Related Goods: Factors Prices of Related Goods: Factors that Shift the Demand Curvethat Shift the Demand Curve

• SubstituteSubstitute——good that can be used in place of some good that can be used in place of some other good and that fulfills more or less the same other good and that fulfills more or less the same purposepurpose

• ExampleExample• A rise in the price of a substitute increases the A rise in the price of a substitute increases the

demand for a good, shifting the demand curve to the demand for a good, shifting the demand curve to the rightright

• Complement—used together with the good we are Complement—used together with the good we are interested ininterested in

• ExampleExample• A rise in the price of a complement decreases the A rise in the price of a complement decreases the

demand for a good, shifting the demand curve to the demand for a good, shifting the demand curve to the leftleft

Other Factors That Shift the Other Factors That Shift the Demand CurveDemand Curve

• PopulationPopulation

• As the population increases in an areaAs the population increases in an area• Number of buyers will ordinarily increaseNumber of buyers will ordinarily increase• Demand for a good will increaseDemand for a good will increase

• Expected PriceExpected Price

• An expectation that price will rise (fall) in the future shifts the An expectation that price will rise (fall) in the future shifts the current demand curve rightward (leftward)current demand curve rightward (leftward)

• TastesTastes

• Combination of all the personal factors that go into determining Combination of all the personal factors that go into determining how a buyer feels about a goodhow a buyer feels about a good

• When tastes change toward a good, demand increases, and the When tastes change toward a good, demand increases, and the demand curve shifts to the rightdemand curve shifts to the right

• When tastes change away from a good, demand decreases, When tastes change away from a good, demand decreases, and the demand curve shifts to the leftand the demand curve shifts to the left

Small SummarySmall Summary-- Factors Affecting Demand-- Factors Affecting Demand

• Income Income (depends on good’s nature: normal or (depends on good’s nature: normal or inferior)inferior)

• WWealth ealth (depends on good’s nature)(depends on good’s nature)

• Prices ofPrices of substitutessubstitutes (positively related) (positively related)

• Prices of complementsPrices of complements (negatively related) (negatively related)

• Population Population (positively related)(positively related)

• Expected priceExpected price (positively related) (positively related)

• TastesTastes (positively related) (positively related)

Figure 3(b): Movements Along and Figure 3(b): Movements Along and Shifts of The Demand CurveShifts of The Demand Curve

Quantity

Price

D2

D1

Entire demand curve shifts rightward when:• income or wealth ↑• price of substitute ↑• price of complement ↓• population ↑• expected price ↑• tastes shift toward good

Figure 3(c): Movements Along and Figure 3(c): Movements Along and Shifts of The Demand CurveShifts of The Demand Curve

Quantity

Price

D1

D2

Entire demand curve shifts leftward when:• income or wealth ↓• price of substitute ↓• price of complement ↑• population ↓• expected price ↓• tastes shift toward good

SummarySummary

Shift of Demand Versus Movement Along a Shift of Demand Versus Movement Along a Demand CurveDemand Curve

• A change in A change in demanddemand is is not the same as a change not the same as a change in in quantity demandedquantity demanded..

• In this example, a higher In this example, a higher price causes lower price causes lower quantity demandedquantity demanded..

• Changes in determinants Changes in determinants of demand, other than of demand, other than price, cause a change in price, cause a change in demanddemand, or a , or a shiftshift of the of the entire demand curve, from entire demand curve, from DDAA to to DDBB..

• When demand shifts to the right, demand increases. This causes quantity demanded to be greater than it was prior to the shift, for each and every price level.

A Change in Demand Versus a Change in A Change in Demand Versus a Change in Quantity DemandedQuantity Demanded

A Change in Demand Versus a Change in A Change in Demand Versus a Change in Quantity DemandedQuantity Demanded

To summarize:

Change in price of a good or service leads to

Change in quantity demanded(Movement along the curve).

Change in income, preferences, orprices of other goods or services

leads to

Change in demand(Shift of curve).

The Impact of a Change in IncomeThe Impact of a Change in Income

• Higher income decreases the demand for an inferior good

• Higher income increases the demand for a normal good

The Impact of a Change in the Price The Impact of a Change in the Price of Related Goodsof Related Goods

• Price of hamburger rises

• Demand for complement good (ketchup) shifts left

• Demand for substitute good (chicken) shifts right

• Quantity of hamburger demanded falls

From Household to Market DemandFrom Household to Market Demand

• Demand for a good or service can be Demand for a good or service can be defined for an defined for an individual householdindividual household, or , or for a group of households that make up a for a group of households that make up a marketmarket..

• Market demandMarket demand is the sum of all the is the sum of all the quantities of a good or service demanded quantities of a good or service demanded per period by all the households buying in per period by all the households buying in the market for that good or service.the market for that good or service.

From Household Demand to Market From Household Demand to Market DemandDemand

• Assuming there are only two households in the Assuming there are only two households in the market, market demand is derived as follows:market, market demand is derived as follows:

To Be ContinuedTo Be Continued