Pertemuan 2 TEORI PERMINTAAN DAN PENAWARAN AGENDA Demand

Pertemuan 2 TEORI PERMINTAAN DAN PENAWARAN

AGENDA �Demand �Supply �Equilibrium

DEMAND � Quantity demanded is the amount of a good that buyers are willing and able to purchase. � Law of Demand � The law of demand states that, other things equal, the quantity demanded of a good falls when the price of the good rises.

THE DEMAND CURVE: THE RELATIONSHIP BETWEEN PRICE AND QUANTITY DEMANDED � Demand � The Schedule demand schedule is a table that shows the relationship between the price of the good and the quantity demanded.

CATHERINE’S DEMAND SCHEDULE

THE DEMAND CURVE: THE RELATIONSHIP BETWEEN PRICE AND QUANTITY DEMANDED � Demand � The Curve demand curve is a graph of the relationship between the price of a good and the quantity demanded.

FIGURE 1 CATHERINE’S DEMAND SCHEDULE AND DEMAND CURVE Price of Ice-Cream Cone $3. 00 2. 50 1. A decrease 2. 00 in price. . . 1. 50 1. 00 0. 50 0 1 2 3 4 5 6 7 8 9 10 11 12 Quantity of Ice-Cream Cones 2. . increases quantity of cones demanded. Copyright © 2004 South-Western

MARKET DEMAND VERSUS INDIVIDUAL DEMAND � Market demand refers to the sum of all individual demands for a particular good or service. � Graphically, individual demand curves are summed horizontally to obtain the market demand curve.

SHIFTS IN THE DEMAND CURVE � Change in Quantity Demanded � Movement along the demand curve. � Caused by a change in the price of the product.

CHANGES IN QUANTITY DEMANDED Price of Ice. Cream Cones B $2. 00 A tax that raises the price of icecream cones results in a movement along the demand curve. A 1. 00 D 0 4 8 Quantity of Ice-Cream Cones

SHIFTS IN THE DEMAND CURVE � Consumer income � Prices of related goods � Tastes � Expectations � Number of buyers

SHIFTS IN THE DEMAND CURVE � Change �A in Demand shift in the demand curve, either to the left or right. � Caused by any change that alters the quantity demanded at every price.

FIGURE 3 SHIFTS IN THE DEMAND CURVE Price of Ice-Cream Cone Increase in demand Demand curve, D 3 0 Demand curve, D 1 Demand curve, D 2 Quantity of Ice-Cream Cones

SHIFTS IN THE DEMAND CURVE � Consumer � As Income increases the demand for a normal good will increase. � As income increases the demand for an inferior good will decrease.

CONSUMER INCOME NORMAL GOOD Price of Ice. Cream Cone An increase in income. . . $3. 00 2. 50 Increase in demand 2. 00 1. 50 1. 00 0. 50 D 1 0 1 2 3 4 5 6 7 8 9 10 11 12 D 2 Quantity of Ice-Cream Cones

CONSUMER INCOME INFERIOR GOOD Price of Ice. Cream Cone $3. 00 An increase in income. . . 2. 50 2. 00 Decrease in demand 1. 50 1. 00 0. 50 D 2 0 1 D 1 2 3 4 5 6 7 8 9 10 11 12 Quantity of Ice-Cream Cones

SHIFTS IN THE DEMAND CURVE � Prices of Related Goods � When a fall in the price of one good reduces the demand for another good, the two goods are called substitutes. � When a fall in the price of one good increases the demand for another good, the two goods are called complements.

TABLE 1 VARIABLES THAT INFLUENCE BUYERS

SUPPLY � Quantity supplied is the amount of a good that sellers are willing and able to sell. � Law of Supply � The law of supply states that, other things equal, the quantity supplied of a good rises when the price of the good rises.

THE SUPPLY CURVE: THE RELATIONSHIP BETWEEN PRICE AND QUANTITY SUPPLIED � Supply � The Schedule supply schedule is a table that shows the relationship between the price of the good and the quantity supplied.

BEN’S SUPPLY SCHEDULE

THE SUPPLY CURVE: THE RELATIONSHIP BETWEEN PRICE AND QUANTITY SUPPLIED � Supply � The Curve supply curve is the graph of the relationship between the price of a good and the quantity supplied.

FIGURE 5 BEN’S SUPPLY SCHEDULE AND SUPPLY CURVE Price of Ice-Cream Cone $3. 00 1. An increase in price. . . 2. 50 2. 00 1. 50 1. 00 0. 50 0 1 2 3 4 5 6 7 8 9 10 11 12 Quantity of Ice-Cream Cones 2. . increases quantity of cones supplied.

MARKET SUPPLY VERSUS INDIVIDUAL SUPPLY � Market supply refers to the sum of all individual supplies for all sellers of a particular good or service. � Graphically, individual supply curves are summed horizontally to obtain the market supply curve.

SHIFTS IN THE SUPPLY CURVE � Input prices � Technology � Expectations � Number of sellers

SHIFTS IN THE SUPPLY CURVE � Change in Quantity Supplied � Movement along the supply curve. � Caused by a change in anything that alters the quantity supplied at each price.

CHANGE IN QUANTITY SUPPLIED Price of Ice. Cream Cone S C $3. 00 A rise in the price of ice cream cones results in a movement along the supply curve. A 1. 00 0 1 5 Quantity of Ice-Cream Cones

SHIFTS IN THE SUPPLY CURVE � Change �A in Supply shift in the supply curve, either to the left or right. � Caused by a change in a determinant other than price.

FIGURE 7 SHIFTS IN THE SUPPLY CURVE Price of Ice-Cream Cone Supply curve, S 3 Decrease in supply Supply curve, S 1 Supply curve, S 2 Increase in supply 0 Quantity of Ice-Cream Cones

TABLE 2 VARIABLES THAT INFLUENCE SELLERS

SUPPLY AND DEMAND TOGETHER � Equilibrium refers to a situation in which the price has reached the level where quantity supplied equals quantity demanded.

SUPPLY AND DEMAND TOGETHER � Equilibrium Price � The price that balances quantity supplied and quantity demanded. � On a graph, it is the price at which the supply and demand curves intersect. � Equilibrium � The Quantity quantity supplied and the quantity demanded at the equilibrium price. � On a graph it is the quantity at which the supply and demand curves intersect.

SUPPLY AND DEMAND TOGETHER Demand Schedule Supply Schedule At $2. 00, the quantity demanded is equal to the quantity supplied!

FIGURE 8 THE EQUILIBRIUM OF SUPPLY AND DEMAND Price of Ice-Cream Cone Supply $2. 00 Equilibrium price Equilibrium quantity 0 1 2 3 4 5 6 7 8 Demand 9 10 11 12 13 Quantity of Ice-Cream Cones

FIGURE 9 MARKETS NOT IN EQUILIBRIUM (a) Excess Supply Price of Ice-Cream Cone Surplus Supply $2. 50 2. 00 Demand 0 4 Quantity demanded 7 10 Quantity of Quantity Ice-Cream supplied Cones

EQUILIBRIUM � Surplus � When price > equilibrium price, then quantity supplied > quantity demanded. � There is excess supply or a surplus. � Suppliers will lower the price to increase sales, thereby moving toward equilibrium.

EQUILIBRIUM � Shortage � When price < equilibrium price, then quantity demanded > the quantity supplied. � There is excess demand or a shortage. � Suppliers will raise the price due to too many buyers chasing too few goods, thereby moving toward equilibrium.

FIGURE 9 MARKETS NOT IN EQUILIBRIUM (b) Excess Demand Price of Ice-Cream Cone Supply $2. 00 1. 50 Shortage Demand 0 4 Quantity supplied 7 10 Quantity of Quantity Ice-Cream demanded Cones

EQUILIBRIUM � Law of supply and demand � The claim that the price of any good adjusts to bring the quantity supplied and the quantity demanded for that good into balance.

THREE STEPS TO ANALYZING CHANGES IN EQUILIBRIUM � Decide whether the event shifts the supply or demand curve (or both). � Decide whether the curve(s) shift(s) to the left or to the right. � Use the supply-and-demand diagram to see how the shift affects equilibrium price and quantity.

FIGURE 10 HOW AN INCREASE IN DEMAND AFFECTS THE EQUILIBRIUM Price of Ice-Cream Cone 1. Hot weather increases the demand for ice cream. . . Supply New equilibrium $2. 50 2. 00 2. . resulting in a higher price. . . Initial equilibrium D D 0 3. . and a higher quantity sold. 7 10 Quantity of Ice-Cream Cones

THREE STEPS TO ANALYZING CHANGES IN EQUILIBRIUM � Shifts in Curves versus Movements along Curves �A shift in the supply curve is called a change in supply. � A movement along a fixed supply curve is called a change in quantity supplied. � A shift in the demand curve is called a change in demand. � A movement along a fixed demand curve is called a change in quantity demanded.

FIGURE 11 HOW A DECREASE IN SUPPLY AFFECTS THE EQUILIBRIUM Price of Ice-Cream Cone S 2 1. An increase in the price of sugar reduces the supply of ice cream. . . S 1 New equilibrium $2. 50 Initial equilibrium 2. 00 2. . resulting in a higher price of ice cream. . . 0 Demand 4 7 3. . and a lower quantity sold. Quantity of Ice-Cream Cones

TABLE 4 WHAT HAPPENS TO PRICE AND QUANTITY WHEN SUPPLY OR DEMAND SHIFTS? Copyright© 2004 South-Western

ELASTICITY. . . � … allows us to analyze supply and demand with greater precision. �… is a measure of how much buyers and sellers respond to changes in market conditions

THE ELASTICITY OF DEMAND � Price elasticity of demand is a measure of how much the quantity demanded of a good responds to a change in the price of that good. � Price elasticity of demand is the percentage change in quantity demanded given a percent change in the price.

THE PRICE ELASTICITY OF DEMAND ITS DETERMINANTS � Availability of Close Substitutes � Necessities versus Luxuries � Definition of the Market � Time Horizon

THE PRICE ELASTICITY OF DEMAND ITS DETERMINANTS � Demand � the tends to be more elastic : larger the number of close substitutes. � if the good is a luxury. � the more narrowly defined the market. � the longer the time period.

COMPUTING THE PRICE ELASTICITY OF DEMAND � The price elasticity of demand is computed as the percentage change in the quantity demanded divided by the percentage change in price.

COMPUTING THE PRICE ELASTICITY OF DEMAND � Example: If the price of an ice cream cone increases from $2. 00 to $2. 20 and the amount you buy falls from 10 to 8 cones, then your elasticity of demand would be calculated as:

THE MIDPOINT METHOD: A BETTER WAY TO CALCULATE PERCENTAGE CHANGES AND ELASTICITIES � The midpoint formula is preferable when calculating the price elasticity of demand because it gives the same answer regardless of the direction of the change.

THE MIDPOINT METHOD: A BETTER WAY TO CALCULATE PERCENTAGE CHANGES AND ELASTICITIES � Example: If the price of an ice cream cone increases from $2. 00 to $2. 20 and the amount you buy falls from 10 to 8 cones, then your elasticity of demand, using the midpoint formula, would be calculated as:

THE VARIETY OF DEMAND CURVES � Inelastic Demand � Quantity demanded does not respond strongly to price changes. � Price elasticity of demand is less than one. � Elastic Demand � Quantity demanded responds strongly to changes in price. � Price elasticity of demand is greater than one.

COMPUTING THE PRICE ELASTICITY OF DEMAND Price $5 4 0 Demand 50 100 Quantity Demand is price elastic

THE VARIETY OF DEMAND CURVES � Perfectly Inelastic � Quantity demanded does not respond to price changes. � Perfectly Elastic � Quantity demanded changes infinitely with any change in price. � Unit Elastic � Quantity demanded changes by the same percentage as the price.

FIGURE 1 THE PRICE ELASTICITY OF DEMAND (a) Perfectly Inelastic Demand: Elasticity Equals 0 Price Demand $5 4 1. An increase in price. . . 0 100 Quantity 2. . leaves the quantity demanded unchanged.

FIGURE 1 THE PRICE ELASTICITY OF DEMAND (b) Inelastic Demand: Elasticity Is Less Than 1 Price $5 4 1. A 22% increase in price. . . Demand 0 90 100 Quantity 2. . leads to an 11% decrease in quantity demanded.

FIGURE 1 THE PRICE ELASTICITY OF DEMAND (c) Unit Elastic Demand: Elasticity Equals 1 Price $5 4 Demand 1. A 22% increase in price. . . 0 80 100 Quantity 2. . leads to a 22% decrease in quantity demanded.

FIGURE 1 THE PRICE ELASTICITY OF DEMAND (d) Elastic Demand: Elasticity Is Greater Than 1 Price $5 4 Demand 1. A 22% increase in price. . . 0 50 100 Quantity 2. . leads to a 67% decrease in quantity demanded.

FIGURE 1 THE PRICE ELASTICITY OF DEMAND (e) Perfectly Elastic Demand: Elasticity Equals Infinity Price 1. At any price above $4, quantity demanded is zero. $4 Demand 2. At exactly $4, consumers will buy any quantity. 0 3. At a price below $4, quantity demanded is infinite. Quantity

Nilai >1 =1 <1 Keterangan Implikasi Elastis % perubahan Q > % perubahan P Unitary Elastis % perubahan Q = % perubahan P Inelastis % perubahan Q < % perubahan P

TOTAL REVENUE AND THE PRICE ELASTICITY OF DEMAND � Total revenue is the amount paid by buyers and received by sellers of a good. � Computed as the price of the good times the quantity sold. TR = P x Q

FIGURE 2 TOTAL REVENUE Price $4 P × Q = $400 (revenue) P Demand 100 0 Q Quantity

ELASTICITY AND TOTAL REVENUE ALONG A LINEAR DEMAND CURVE � With an inelastic demand curve, an increase in price leads to a decrease in quantity that is proportionately smaller. Thus, total revenue increases.

FIGURE 3 HOW TOTAL REVENUE CHANGES WHEN PRICE CHANGES: INELASTIC DEMAND Price An Increase in price from $1 to $3 … … leads to an Increase in total revenue from $100 to $240 $3 Revenue = $240 $1 0 Demand Revenue = $100 Quantity 0 80 Quantity

ELASTICITY AND TOTAL REVENUE ALONG A LINEAR DEMAND CURVE � With an elastic demand curve, an increase in the price leads to a decrease in quantity demanded that is proportionately larger. Thus, total revenue decreases.

FIGURE 4 HOW TOTAL REVENUE CHANGES WHEN PRICE CHANGES: ELASTIC DEMAND Price An Increase in price from $4 to $5 … … leads to an decrease in total revenue from $200 to $100 $5 $4 Demand Revenue = $200 0 50 Revenue = $100 Quantity 0 20 Quantity

ELASTICITY OF A LINEAR DEMAND CURVE

INCOME ELASTICITY OF DEMAND � Income elasticity of demand measures how much the quantity demanded of a good responds to a change in consumers’ income. � It is computed as the percentage change in the quantity demanded divided by the percentage change in income.

COMPUTING INCOME ELASTICITY

INCOME ELASTICITY � Types of Goods � Normal Goods � Inferior Goods � Higher income raises the quantity demanded for normal goods but lowers the quantity demanded for inferior goods.

INCOME ELASTICITY � Goods consumers regard as necessities tend to be income inelastic � Examples include food, fuel, clothing, utilities, and medical services. � Goods consumers regard as luxuries tend to be income elastic. � Examples include sports cars, furs, and expensive foods.

IMPLIKASI Nilai Golongan Barang interprestasi Positif Income-Normal barang normal, kenaikan pendapatan akan berpengaruh dengan kenaikan jumlah barang yang diminta. Nol Income-Independen barang netral, kenaikan / penurunan pendapatan tidak berpengaruh terhadap jumlah konsumsi Negatif Income-Inferior konsumsi akan

CROSS ELASTICITY � Cross elasticity of demand measures how much the quantity demanded of a good responds to a change in the other price. � It is computed as the percentage change in the quantity demanded divided by the percentage change in the other price

COMPUTING CROSS ELASTICITY = % Change in Quantity Demanded Y % Change in The Other Price (X)

IMPLIKASI NILAI Positif JENIS BARANG Subtitusi IMPLIKASI Barang-barang bisa saling mengganti satu sama lain Nol Independen Barang-barang tersebut tidak berhubungan dalam pengkonsumsiannya Negatif Komplementer Barang-barang tersebut dikonsumsi secara bersama-

THE ELASTICITY OF SUPPLY � Price elasticity of supply is a measure of how much the quantity supplied of a good responds to a change in the price of that good. � Price elasticity of supply is the percentage change in quantity supplied resulting from a percent change in price.

FIGURE 6 THE PRICE ELASTICITY OF SUPPLY (a) Perfectly Inelastic Supply: Elasticity Equals 0 Price Supply $5 4 1. An increase in price. . . 0 100 Quantity 2. . leaves the quantity supplied unchanged.

FIGURE 6 THE PRICE ELASTICITY OF SUPPLY (b) Inelastic Supply: Elasticity Is Less Than 1 Price Supply $5 4 1. A 22% increase in price. . . 0 100 110 Quantity 2. . leads to a 10% increase in quantity supplied.

FIGURE 6 THE PRICE ELASTICITY OF SUPPLY (c) Unit Elastic Supply: Elasticity Equals 1 Price Supply $5 4 1. A 22% increase in price. . . 0 100 125 Quantity 2. . leads to a 22% increase in quantity supplied.

FIGURE 6 THE PRICE ELASTICITY OF SUPPLY (d) Elastic Supply: Elasticity Is Greater Than 1 Price Supply $5 4 1. A 22% increase in price. . . 0 100 200 Quantity 2. . leads to a 67% increase in quantity supplied.

FIGURE 6 THE PRICE ELASTICITY OF SUPPLY (e) Perfectly Elastic Supply: Elasticity Equals Infinity Price 1. At any price above $4, quantity supplied is infinite. $4 Supply 2. At exactly $4, producers will supply any quantity. 0 3. At a price below $4, quantity supplied is zero. Quantity

DETERMINANTS OF ELASTICITY OF SUPPLY � Ability of sellers to change the amount of the good they produce. � Beach-front land is inelastic. � Books, cars, or manufactured goods are elastic. � Time period. � Supply is more elastic in the long run.

COMPUTING THE PRICE ELASTICITY OF SUPPLY � The price elasticity of supply is computed as the percentage change in the quantity supplied divided by the percentage change in price.

THE APPLICATION OF SUPPLY, DEMAND, AND ELASTICITY � Examine whether the supply or demand curve shifts. � Determine the direction of the shift of the curve. � Use the supply-and-demand diagram to see how the market equilibrium changes.

FIGURE 8 AN INCREASE IN SUPPLY IN THE MARKET FOR WHEAT Price of Wheat 2. . leads to a large fall in price. . . 1. When demand is inelastic, an increase in supply. . . S 1 S 2 $3 2 Demand 0 100 110 Quantity of Wheat 3. . and a proportionately smaller increase in quantity sold. As a result, revenue falls from $300 to $220.

ELASTICITY AND TAX INCIDENCE � Tax incidence is the manner in which the burden of a tax is shared among participants in a market.

ELASTICITY AND TAX INCIDENCE � Tax incidence is the study of who bears the burden of a tax. � Taxes result in a change in market equilibrium. � Buyers pay more and sellers receive less, regardless of whom the tax is levied on.

FIGURE 6 A TAX ON BUYERS Price of Ice-Cream Price Cone buyers pay $3. 30 Price 3. 00 2. 80 without tax Price sellers receive Supply, S 1 Equilibrium without tax Tax ($0. 50) Equilibrium with tax A tax on buyers shifts the demand curve downward by the size of the tax ($0. 50). D 1 D 2 0 90 100 Quantity of Ice-Cream Cones

ELASTICITY AND TAX INCIDENCE � What was the impact of tax? � Taxes discourage market activity. � When a good is taxed, the quantity sold is smaller. � Buyers and sellers share the tax burden.

FIGURE 7 A TAX ON SELLERS Price of Ice-Cream Price Cone buyers pay $3. 30 3. 00 Price 2. 80 without tax S 2 Equilibrium with tax S 1 Tax ($0. 50) A tax on sellers shifts the supply curve upward by the amount of the tax ($0. 50). Equilibrium without tax Price sellers receive Demand, D 1 0 90 100 Quantity of Ice-Cream Cones

PERBEDAAN KONSEP � Menurut Ibnu Taimiyyah, permintaan suatu barang adalah hasrat terhadap sesuatu. � Konsep permintaan merupakan hubungan antara jumlah barang yang diminta dengan berbagai tingkat harga.

HUKUM PERMINTAAN � pada masa zaman sebelum kenabian atau sesudah masa kenabian, sudah ada pemikiran yang menjadi kesepakatan bersama bahwa tinggi rendahnya pemintaan terhadap barang ditentukan oleh harga barang yang bersangkutan. � Abu Yusuf mengatakan “Kadang-kadang makanan melimpah, tetapi tetap mahal dan kadang-kadang makanan sangat sedikit tetapi murah”

LANDASAN FILOSOFI Islam dalam hal ini khususnya perekonomian sangat menjunjung nilai kesederhanaan. Ø norma-norma Islam yang selalu menemani kehidupan manusia yaitu halal dan haram. Ø

IBNU TAIMIYYAH (1263 -1328 M) DALAM KITAB MAJMU’ FATAWA hal-hal yang mempengaruhi terhadap permintaan suatu barang: � Keinginan atau selera masyarakat � Jumlah para peminat (Tullab) � Kualitas pembeli (Al-Mu’awid) � Lemah atau kuatnya kebutuhan terhadap suatu barang. � Besarnya biaya transaksi.

FAKTOR-FAKTOR PENAWARAN DALAM ISLAM � Mashlahah � Keuntungan

PERBEDAAN TEORI PERMINTAAN KONVENSIONAL DENGAN PERMINTAAN ISLAMI Men Islami : Ø Permintaan Islam bukan hanya berasal dari data pengalaman tapi juga berasal dari firman-firman Allah. Ø Konsep permintaan dalam Islam menilai suatu komoditi tidak semuanya bisa untuk dikonsumsi maupun digunakan. Ø Dalam motif permintaan Islam menekankan pada tingkat kebutuhan konsumen terhadap barang

Men Konvensional : Ø ekonomi konvensional filosofi dasarnya terfokus pada tujuan keuntungan dan material. Ø dalam permintaan konvensional, semua komoditi dinilai sama, bisa dikonsumsi atau digunakan. Ø motif permintaan konvensional lebih didominasi oleh nilai-nilai kepuasani.