APLIKASI MEKANISME PASAR PERMINTAAN DAN PENAWARAN Mikro Ekonomi

APLIKASI MEKANISME PASAR: PERMINTAAN DAN PENAWARAN Mikro Ekonomi

QUIZ • • What is demand & supply laws? Explain! Draw demand & supply curves! What are factors affecting demand & supply? What is movement along the demand & supply curves? Explain! • How shifting in the demand & supply curves may happen? Explain! 2

FUNGSI PERMINTAAN • Fungsi permintaan adalah permintaan yang dinyatakan dalam hubungan matematis dengan faktor-faktor yang memengaruhinya. • Dengan menggunakan fungsi ini, maka kita akan mengetahui hubungan antara variable tidak bebas (dependent variable) dan variable-variabel bebas (independent variables). • Misal, fungsi permintaan beras di Kota Brebes per bulan merupakan fungsi linear berikut ini, Qd = 100 – 10 P 3

FUNGSI PENAWARAN • Fungsi penawaran adalah penawaran yang dinyatakan dalam hubungan matematis dengan faktor-faktor yang memengaruhinya. • Sx = f(Px, Py, Pi, C, tek, ped, tuj, kebij) 4

KURVA PERMINTAAN INDIVIDUAL DAN PASAR FIGURE 3. 5 Deriving Market Demand from Individual Demand Curves Total demand in the marketplace is simply the sum of the demands of all the households shopping in a particular market. It is the sum of all the individual demand curves—that is, the sum of all the individual quantities demanded at each price. 5

KURVA PENAWARAN INDIVIDUAL DAN PASAR FIGURE 3. 8 Deriving Market Supply from Individual Firm Supply Curves Total supply in the marketplace is the sum of all the amounts supplied by all the firms selling in the market. It is the sum of all the individual quantities supplied at each price. 6

PERUBAHAN PENDAPATAN DAN PERUBAHAN HARGA BARANG YANG BERSANGKUTAN • Shift of a demand curve The change that takes place in a demand curve corresponding to a new relationship between quantity demanded of a good and price of that good. The shift is brought about by a change in the original conditions. • Movement along a demand curve The change in quantity demanded brought about by a change in price. Change in price of a good or service leads to Change in quantity demanded (movement along a demand curve). Change in income, preferences, or prices of other goods or services leads to Change in demand (shift of a demand curve). 7

PERUBAHAN PENDAPATAN DAN PERUBAHAN HARGA BARANG YANG BERSANGKUTAN TABLE 3. 2 Shift of Alex’s Demand Schedule Due to Increase in Income Schedule D 0 Schedule D 1 Quantity Demanded (Gallons per Week at an Income of $550 per Week) Quantity Demanded (Gallons per Week at an Income of $730 per Week) $ 8. 00 0 3 7. 00 2 5 6. 00 3 7 5. 00 5 10 4. 00 7 12 3. 00 10 15 2. 00 14 19 1. 00 20 24 0. 00 26 30 Price (per Gallon) FIGURE 3. 3 Shift of a Demand Curve following a Rise in Income When the price of a good changes, we move along the demand curve for that good. When any other factor that influences demand changes (income, tastes, and so on), the relationship between price and quantity is different; there is a shift of the demand curve, in this case from D 0 to D 1. Gasoline is a normal good. 8

PERUBAHAN PENDAPATAN DAN PERUBAHAN HARGA BARANG YANG BERSANGKUTAN FIGURE 3. 4 Shifts versus Movement Along a Demand Curve a. When income increases, the demand for inferior goods shifts to the left and the demand for normal goods shifts to the right. 9

PERUBAHAN PENDAPATAN DAN PERUBAHAN HARGA BARANG YANG BERSANGKUTAN FIGURE 3. 4 Shifts versus Movement Along a Demand Curve (continued) b. If the price of hamburger rises, the quantity of hamburger demanded declines— this is a movement along the demand curve. The same price rise for hamburger would shift the demand for chicken (a substitute for hamburger) to the right and the demand for 10 ketchup (a complement to hamburger) to the left.

PERUBAHAN BIAYA DAN PERUBAHAN HARGA BARANG YANG BERSANGKUTAN • Shift of a supply curve The change that takes place in a supply curve corresponding to a new relationship between quantity supplied of a good and price of that good. The shift is brought about by a change in the original conditions. • Movement along a supply curve The change in quantity supplied brought about by a change in price. Change in price of a good or service leads to Change in quantity supplied (movement along a supply curve). Change in costs, input prices, technology, or prices of related goods and services leads to Change in supply (shift of a supply curve). 11

PERUBAHAN BIAYA DAN PERUBAHAN HARGA BARANG YANG BERSANGKUTAN TABLE 3. 4 Shift of Supply Schedule for Soybeans following Development of a New Disease. Resistant Seed Strain Price (per Bushel) Schedule S 0 Schedule S 1 Quantity Supplied (Bushels per Year Using Old Seed) Quantity Supplied (Bushels per Year Using New Seed) $1. 50 0 5, 000 1. 75 10, 000 23, 000 2. 25 20, 000 33, 000 30, 000 45, 000 54, 000 5. 00 45, 000 54, 000 FIGURE 3. 7 Shift of the Supply Curve for Soybeans following Development of a New Seed Strain When the price of a product changes, we move along the supply curve for that product; the quantity supplied rises or falls. When any other factor affecting supply changes, the supply curve shifts. 12

KASUS PENGECUALIAN • Ada (3) tiga kelompok barang di mana hukum permintaan tidak berlaku: – Barang yang memiliki unsur spekulasi, contohnya emas, saham, dan tanah. – Barang prestise, contohnya mobil mewah, lukisan dari pelukis terkenal, atau barang antik. – Barang giffen, contohnya pakaian yang dijual di tempat penjualan barang bekas. • Pada hukum penawaran sering kita jumpai adalah pada kasus penawaran akan tenaga kerja yang digambarkan oleh backward bending labour supply curve 13

PENGEMBANGAN MATEMATIS TENTANG PERUBAHAN HARGA • Persamaan permintaan Qd = c – d. P • Persamaan penawaran Qs = -m + n. P • Sehingga Qd = Qs c – d. P = -m + n. P 14

PENGEMBANGAN MATEMATIS TENTANG PERUBAHAN HARGA • Contoh perhitungan Qd = 200 – 10 P Qs = -40 + 5 P Berapa harga keseimbangan? • Contoh perhitungan Qd = 22000 – 2 P Qs = -3000 + 3 P Berapa harga keseimbangan? 15

PREFERENSI YANG DINYATAKAN DAN EFEK SUBSTITUSI Y • Efek Substitusi, bilamana terjadi kenaikan harga barang X akan menyebabkan naiknya permintaan barang Y. • Efek Pendapatan, Naiknya harga barang X berakibat penurunan relatif pendapatan konsumen. A C B IC 2 IC 1 0 X 1 X 3 X 2 A 1 A 2 X Keterangan: X 1 X 2 total efek X 1 X 3 efek substitusi X 3 X 2 efek pendapatan 16

PREFERENSI YANG DINYATAKAN DAN EFEK SUBSTITUSI Y Keterangan: Barang Inferior, Kenaikan pendapatan konsumen akan menurunkan jumlah barang X yang diminta. X 1 X 2 total efek X 1 X 3 efek substitusi X 3 X 2 efek pendapatan A B IC 2 C IC 1 0 X 1 X 2 X 3 A 1 A 2 A 3 X 17

PREFERENSI YANG DINYATAKAN DAN EFEK SUBSTITUSI Y Barang Giffen, sifatnya menyerupai barang inferior, sifat khususnya adalah jika harga barang inferior turun jumlah permintaan juga akan turun. Keterangan: B X 1 X 2 total efek X 1 X 3 total substitusi X 2 X 3 efek pendapatan IC 2 A C IC 1 0 X 2 X 1 X 3 A 1 A 2 A 3 X 18

SURPLUS KONSUMEN & PRODUSEN • Consumer surplus The difference between the maximum amount a person is willing to pay for a good and its current market price. • Producer surplus The difference between the current market price and the full cost of production for the firm. 19

SURPLUS KONSUMEN FIGURE 4. 6 Market Demand Consumer Surplus As illustrated in (a), some consumers (see point A) are willing to pay as much as $5. 00 each for hamburgers. Since the market price is just $2. 50, they receive a consumer surplus of $2. 50 for each hamburger that they consume. Others (see point B) are willing to pay something less than $5. 00 and receive a slightly smaller surplus. Since the market price of hamburgers is just $2. 50, the area of the shaded triangle in (b) is equal to total consumer surplus. 20

SURPLUS PRODUSEN FIGURE 4. 7 Market Supply and Producer Surplus As illustrated in (a), some producers are willing to produce hamburgers for a price of $0. 75 each. Since they are paid $2. 50, they earn a producer surplus equal to $1. 75. Other producers are willing to supply hamburgers at a price of $1. 00; they receive a producer surplus equal to $1. 50. Since the market price of hamburgers is $2. 50, the area of the shaded triangle in (b) is equal to total producer surplus. 21

HARGA KESEIMBANGAN Competitive Markets Maximize the Sum of Producer and Consumer Surplus FIGURE 4. 8 Total Producer and Consumer Surplus Total producer and consumer surplus is greatest where supply and demand curves intersect at equilibrium. 22

REFERENCES • Case, Karl E. , Ray C. Fair & Sharon M. Oster. 2013. Principles of Economics. Pearson Education Limited. • Rahardja, Pratama dan Mandala Manurung. 2010. Teori Ekonomi Mikro: Suatu Pengantar. Jakarta: LPFE-UI • Salvatore, Dominick. 2006. Microeconomics, Fourth Edition. Jakarta: Penerbit Erlangga. • Sukirno, Sadono. 2015. Mikroekonomi Teori Pengantar. Jakarta: Rajawali Pers. 23