Chapter 3Demand Theory(Teori Permintaan)

The Demand for CommodityPrice Elasticity of DemandIncome Elasticity of DemandCross-price Elasticity of DemandUsing Elasticity's in Managerial Decision Makingpp. 86-1363.1. The Demand for CommodityAn Individuals Demand for a CommodityFrom Individual to Market DemandThe Demand Faced by a Firm

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *An Individual Consumers Demand QdX = f(PX, I, PY, T)quantity demanded of commodity X by an individual per time periodprice per unit of commodity Xconsumers incomeprice of related (: substitute or complementary) commoditiestastes of the consumerQdX = PX =I =PY = T =

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Permintaan Individual Konsumen QdX = f(PX, I, PY, T)Kuantitas yg diminta dari barang X oleh individual pd waktu tertentuharga per unit barang Xpendapatan konsumenHarga barang yg terkait (: substitusi atau saling melengkapi)Selera konsumenQdX = PX =I =PY = T =

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Law of DemandThere is an inverse relationship between the price of a good and the quantity of the good demanded per time period.Substitution Effect: QdX/PY > 0 Income Effect: inferior & normal goods

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Hukum PermintaanHubungan yg berlawanan antara harga brg dan jumlah brg yang diminta dlm periode tertentu. Dampak Substitusi: QdX/PY > 0 hub positif)Dampak Income: inferior & normal goods

Prices of Related GoodsThe quantity of one goods that consumers plan to buy does not depend only on the prices of that goods. These related goods fall into two categories:Substitutea good that can be used in place of another good TV Sharp VS TV Toshiba

Complementa good used in conjunction with another good Oil VS Car

Harga dari Barang TerkaitJumlah suatu barang yg akan dibeli konsumen tidak tergantung hanya pada harga saja. Barang dikelompokkan dalam 2 katagori: SubstitusiSuatu brg dpt digunakan utk menggantikan brg lainnya TV Sharp VS TV Toshiba

Komplemen (Saling membutuhkan)Suatu brg digunakan bersamaan dg barang lainnya BBM VS Mobil

IncomeNormal Goodsgoods that do increase in demand as income increases

Inferior Goodsgoods that decrease in demand as income increasesAlthough an increase in income leads to an increase in the demand for most goods, income does not lead to an increase in the demand for all goods.

PendapatanBarang Normal Permintaan thd brg meningkat jika pendapatan naik

Barang InferiorPermintaan thd brg menurun jika pendapatan meningkat. Walaupun kenaikkan pendapatan mengakibtkan kenaikkan permintaan thd brg pd umumnya, pendapatan tidak menyebabkan kenaikkan permintaan seluruh barang.

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Hukum PermintaanHubungan yang berlawanan antara harga barang dan jumlah barang yang diminta per satuan waktu.Efek substitusi: QdX/PY > 0 (Dampak harga barang subsitusi positif)Efek pendapatan: inferior & normal goods ( negatif dan positif)

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *An Individuals Demand for a CommodityQuantityPriceP0Q0Q1dx shifts to the right or to the left due to change of consumers incomep. 90Income

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Permintaan Individual thd KomoditiQuantityPriceP0Q0Q1Kurva permintaan bergeser ke kiri atau ke kanan karena perobahan tingkat pendapatanp. 90Pendapatan

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *QdX = f(PX, I, PY, T)QdX/PX < 0 Px Dx QdX/I > 0 if a good is normal: I Dx QdX/I < 0 if a good is inferior: I Dx QdX/PY > 0 if X and Y are substitutes: Py Dx QdX/PY < 0 if X and Y are complements: Py Dx

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Market Demand Function QDX = f(PX, N, I, PY, T)quantity demanded of commodity Xprice per unit of commodity Xnumber of consumers on the marketconsumer incomeprice of related (substitute or complementary) commodityconsumer tastesQDX =PX =N =I =PY = T =

Market Demand CurveHorizontal summation of demand curves of individual consumers

Bandwagon Effect: (keep up with the Joneses)Snob Effect: (exclusive) : buy fewer if many people buy more Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *p. 92

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Kurva Permintaan PasarPenjumlahan mendatar kurva permintaan dari individual konsumen

Dampak Bandwagon: membeli karena mengikuti selera orang lain Dampak Snobis: membeli sedikit jika banyak orang membeli barang tsb (exclusive)p. 92

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Horizontal Summation: From Individual to Market Demand

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Penjumlahan Mendatar: Dari Individual menjadi Permintaan Pasar

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Demand Faced by a FirmMarket StructureMonopoly: the sole producerOligopoly: a few firms in the industry (cigarettes)Monopolistic Competition: many firms selling a differentiated product in the industry Chapter 9 monopoly + competitionPerfect Competition: demand curve is horizontal; many sellers n buyersType of GoodDurable GoodsNondurable GoodsProducers Goods (D for capital equipment)- Derived Demand (demand for inputs depends on D for goods) p. 93

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Permintaan yg Dihadapi PerusahaanStruktur PasarMonopoly: produsen tunggal: listrik, telepon, transportasiOligopoly: beberapa perusahaan dalam industry (rokok)Persaingan Monopolistik: banyak perus menjual produk terdiferensiasi atau heterogen Chapter 9 monopoly + competitionPerfect Competition: kurva permintaan horizontal; banyak penjual dan pembeliTipe BarangBarang tahan lama: mobilBarang mudah rusak: makananBarang-barang produsen (peralatan modal, )- Permintaan Turunan (permintaan thd inputs tergantung D thd barang) p. 93

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Persaingan:Ketersediaan kredit dan i permintaan

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3.2. Price Elasticity of DemandLinear FunctionPoint Definition(Point price elasticityof demand)See: p. 100p.98The Demand Function Faced by a Firmif Px = 0

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3.2. Price Elasticity of DemandLinear FunctionPoint Definition(Point price elasticityof demand)See: p. 100p.98Fungsi D yang Dihadapi Perusahaanif Px = 0 Fungsi Permintaan Linear Titik potong

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3.2. Price Elasticity of DemandLinear FunctionPoint Definition(Point price elasticityof demand)See: p. 100p.98Ep = negative QDs = 7,609 1,606P + 59N + 947I + ---- s = sweet potatoesN= 208,78; I= 3,19; Pw= 2,41; t= 24QDs = 19,306 1,606P See demand functionp. 96 a1 = -1,606QDs at $7 = -7 x 1,606 + 19,306 = 8,064 Ep = -1,606 (7/8,064) = - 1,39 hal 103-104

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3.2. Price Elasticity of Demand(Elastisitas Permintaan thd Harga)Linear FunctionDefinisi Titik:Elastisitas Titik Permintaan thd HargaSee: p. 100 5th edp.98Ep = negative See demand functionp. 96 a1 = -1,606QDs at $7 = -7 x 1,606 + 19,306 = 8,064 Ep = -1,606 (7/8,064) = - 1,39 hal 103-104QDs = 7,609 1,606P + 59N + 947I + ---- hal 103N= 208,78; I= 3,19; Pw= 2,41; t= 24QDs = 19,306 1,606P

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Price Elasticity of Demand Elastisitas Permintaan thd HargaArc Definitionp. 101 Between two points on the demand curve: see Figure 3-4

Price Elasticity of Demand Elastisitas Permintaan thd Harga Difinisi Busurp. 101 Antara dua titik pada kurva D: see Figure 3-4Hal 107200300FC43 Ep = - 1,4 hal 1080

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Completely Inelastic Demand Curve: = 0Price per unit ($)

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Completely Elastic Demand Curve: = - 8Perfectly competitive firmDx = P = MR

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Price Elasticity of Demand Varies Along a Linear Demand Curve

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Elastisitas Permintaan thd Harga Berbeda Sepanjang Kurva Permintaan Linear

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Marginal Revenue and Price Elasticity of DemandTR = P.Q

d(P.Q)MR = = P + Q dP/dQ = P(1 + dP/dQ. Q/P) dQp. 103Ep = -1 MR = 0

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Pendapatan Marginal dan Elastisitas Permintaan thd HargaTR = P.Q

d(P.Q)MR = = P + Q dP/dQ = P(1 + dP/dQ. Q/P) dQp. 103Ep = -1 MR = 0

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Marginal Revenue and Price Elasticity of DemandPXQXMRXp. 10430036

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Pendapatan Marginal dan Elastisitas Permintaan thd HargaPXQXMRXp. 10430036

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Marginal Revenue, Total Revenue, and Price ElasticityTRQXTR = P.Q = 6Q - Q /100MR = 6 Q/50MR = 0 Q = 300p. 104300

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Pendapatan Marginal , Total Pendapatan, & Elastisitas HargaTRQXTR = P.Q = 6Q - Q /100MR = 6 Q/50MR = 0 Q = 300p. 104300

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Relations Among Price Elasticity and Marginal, Average, and Total Revenuep. 104

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Hubungan antara Elastisitas Harga dan Pendapatan Marginal, Rata-rata, dan Total p. 104

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Determinants of Price Elasticity of DemandDemand for a commodity will be more elastic if:It has many close substitutes: sugar >< saltIt is narrowly defined: coke >< general soft drinksMore time is available to adjust to a price change: gasolinep. 106

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide * Penentu dari Elastisitas Permintaan thd Harga Permitaan thd komoditi akan lebih elastik jika:Mempunyai banyak substitusinya: gula >< garamSemakin sempit didifinisikan: coke >< minuman ringan yg umumLebih panjang waktu yg tersedia untuk menyesuaikan perobahan harga: bensinp. 106

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Determinants of Price Elasticity of DemandDemand for a commodity will be less elastic if:It has few substitutesIt is broadly definedLess time is available to adjust to a price changep. 106

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Penentu dari Elastisitas Permintaan thd HargaPermintaan thd komoditi akan kurang elastis jika:Substitusinya sedikitSemakin luas komoditas didifinisikan: coca-cola dan minuman ringan Lebih singkat waktu untuk menyesuaikan perobahan harga p. 106

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3-3 Income Elasticity of Demand

Linear FunctionPoint Definitionp. 108

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3-3 Elastisitas Permintaan thd Pendapatan

Fungsi LinearDefinisi Titikp. 108

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Income Elasticity of Demand (Elastisitas Permintaan thd Pendapatan)Arc DefinitionNormal GoodInferior Good

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Elastisitas Permintaan thd PendapatanDefinisi BusurBarang NormalBarang Inferior

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *3-4 Cross-Price Elasticity of Demand(Elastisitas Permintaan Silang thd Harga)Linear FunctionPoint Definitionpp. 110 - 112

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Cross-Price Elasticity of Demand (Elastisitas Permintaan Silang thd Harga)Arc DefinitionSubstitutesComplementsSubsitutes: coffee-tea, electric-gass, cocacola-pepsi Complements: coffee-sugar, car-fuel, hotdog-mustard

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Other Factors Related to Demand TheoryInternational Convergence of TastesGlobalization of MarketsInfluence of International Preferences on Market DemandGrowth of Electronic CommerceCost of SalesSupply Chains and LogisticsCustomer Relationship Managementp. 117p.118

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *Faktor lain yg terkait dengan Teori PermintaanMenyatunya selera secara internasional Globalisasi pasarPengaruh dari preferensi internasional thd permintaan pasarBerkembanganya perdagangan dengan internet (e-commerce)Biaya penjualanRantai pemasok dan LogistikManajemen hubungan pelangganp. 117p.118

CASE APPLICATION 3-2QDs = 7,609 1,606Ps + 59N + 947I + 479Pw 271t (3-4) EXY = 479 (2.94/10,312) = 0.14 Exy = 0.14A 10 % increase in the price of white potatoes (Pw) would have resulted in only a 1.4% increase in the demand of for sweet potatoes (Qs) X = Sweet ptts; Y = White ptts p. 96p. 111Ps = $5.6; N= 150.73; I= 1.76; Pw= $2.94; t= 1 Qs= 10.312 p. 111

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *LATIHANQc = 100.000 100Pc + 2.000N + 50I +30Pf 1.000Pg + 3A + 40.000PiQc = Jumlah permintaan mobil ChevroletPc = Harga mobil ChevroletN = Jumlah populasi/jutaI = Pendapatan per kapitaPf = Harga mobil FordPg = Harga BBMA = Biaya iklan ChevroletPi = Insentif kredit utk membeli Chevrolet/ %

p. 128, # 2(a) Tunjukkan perubahan permintaan Chevrolet setiap perubahan indep. variblesHitung Qc jika nilai indep variables adalah Pc N I ..Dapatkan persamaan kurva permintaan chevroletGambarkan butir (c) hal 137Answer: p.619

Prepared by Robert F. Brooker, Ph.D. Copyright 2004 by South-Western, a division of Thomson Learning. All rights reserved.Slide *No. 8Koefisien Pendapatan dalam satu regresi dari permintaan = 10(a) Hitung elastisitas pendapatan pada pendapatan $10.000,- dan penjualan 80.000 units(b) Berapa elastisitas pendapatan jika penjualan naik dari 80.000 menjadi 90.000 units dan pendapatan naik dari $10.000 menjadi $11.000?

Hal 138; p. 129

Improved by Nurzaman BachtiarImproved by Nurzaman BachtiarJanuary 2012Managerial Economics, Ch. 3*Managerial Economics, Ch. 3Improved by Nurzaman BachtiarImproved by Nurzaman BachtiarJanuary 2012Managerial Economics, Ch. 3*Managerial Economics, Ch. 3