7 Konsumen, Produsen, dan Efisiensi Pasar P R I N C I P L E S O F F O U R T H E D I T I O N This is a very theoretical chapter. Most students in principles-level courses are a bit less patient with theory than with real-world applications. However, you can tell your students that learning the material in this chapter will pay off in (at least) two ways. First, the tools introduced in this chapter (consumer & producer surplus, welfare economics) are used extensively in the real world to assess the costs and benefits of policies and market imperfections. When does a policy do more harm than good? Who does the policy make better off, and who is made worse off? How do the total gains to the winners compare to the total losses incurred by the losers? The following two chapters will use the tools of welfare economics to analyze taxes and international trade (including restrictions on trade). Students typically find these applications very interesting, and they are much easier to learn after students have a good working knowledge of the material covered in this chapter. Second, the theory in this chapter illuminates one of the most important ideas in economics: Adam Smith’s invisible hand, a.k.a. the principle that markets are usually a good way to organize economic activity.

Pada Bagian ini bertujuan untuk menjawab pertanyaan-pertanyaan seperti berikut: Apa yang dimaksud surplus konsumen? Bagaimana hal ini berhubungan dengan kurva permintaan? Apa yang dimaksud dengan surplus produsen? Bagaimana hal ini berhubungan dengan kurva penawaran? Apakah pasar dapat menghasilkan alokasi sumber daya yang diinginkan? Or could the market outcome be improved upon? CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Welfare Economics Mengulang kembali, bahwa alokasi sumber daya mengacu pada: Berapa banyak barang yang dapat dihasilkan Produsen yang memproduksi Konsumen yang mengkonsumsi Welfare economics: ilmu yang mempelajari bagaimana alokasi sumber daya mempengaruhi kesejahteraan ekonomi Pertama, kita akan melihat kesejahteraan konsumen. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Willingness to Pay (WTP) WTP adalah jumlah maksimum yang akan pembeli bayar untuk suatu barang. Contoh: 4 pembeli yang memiliki WTP untuk baju batik. Nama WTP Budi $250 Rama 175 Jodi 300 Togar 125 FYI: The four guys in this example are the members of the Red Hot Chili Peppers. In the corresponding example from the textbook, Mankiw uses the Beatles. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

WTP dan Kurva Permintaan Pertanyaan: Jika harga dari baju batik adalah $200, siapa yang akan membeli barang tersebut? dan berapa jumlah kuantitas yang diminta? Jawaban: Budi & Jodi akan membeli batik, Rama & Togar tidak akan membeli. oleh sebab itu, Qd = 2 Ketika P = $200 Nama WTP Budi $250 Rama 175 Jodi 300 Togar 125 CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

WTP dan Kurva Permintaan Skedul Permintaan: P (harga batik*) Pembeli Qd 301 ke atas Tidak ada pembeli Nama WTP Budi $250 Rama 175 Jodi 300 Togar 125 251 – 300 Jodi 1 176 – 250 Jodi dan Budi 2 Give your students a few moments to fill in the table. Then, reveal the answers. Then, tell them that they have just constructed the demand schedule for iPods. Next, we will use the demand schedule to draw the demand curve (just like in Chapter 4 when we first covered demand schedules & curves). 126 – 175 Rama, Jodi, Budi 3 0 – 125 Budi, Togar, Rama, Jodi 4 CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

WTP dan Kurva Permintaan Qd 301 up 251 – 300 1 176 – 250 2 126 – 175 3 0 – 125 4 The table on this slide consists of the 1st and 3rd columns of the table on the preceding slide. The numbers in these columns are the demand schedule for iPods, and give us the demand curve shown in the graph on this slide. The animation is as follows: When P is $301 or higher, Qd is zero. That part of the table is highlighted when the upper-most segment of the demand curve is revealed. If the price falls to $300, then Qd increases to 1. If the price is anywhere in the range $251-300, Qd = 1. If the price falls to $250, then Qd increases to 2. If the price is anywhere in the range $176-250, Qd = 2. …and so forth. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Penjelasan Bentuk Tangga Kurva D terlihat seperti tangga dengan 4 tahap– 1 tahap per pembeli. Pasar persaingan sempurna memiliki jumlah pembeli yang besar, Semakin banyak pembeli, maka step semakin kecil, Dan akan membuat kurva D lebih smooth After the previous slide, most of your students will probably understand where this D curve comes from, but its staircase-like shape will seem quite odd to them. Point out that it has 4 “steps,” one for each buyer. Suppose there were 10 buyers instead of 4; how many steps would it have? Ten, of course. If there were 20 buyers, this D “curve” would have 20 steps. A perfectly competitive market has a huge number of buyers. Suppose there were 10,000 buyers in the market for iPods (a tiny fraction of the actual number of buyers!). Then, the number of steps would be 10,000. In relation to the graph, each step would be insignificantly small, and the D curve would look like a smooth curve rather than a staircase – even though it really is a staircase – one with 10,000 infinitesimally small steps. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

WTP and the Demand Curve Pada setiap Q, ketinggian dari kurva D adalah WTP dari marginal buyer, pembeli akan meninggalkan pasar jika P lebih tinggi. Jodi WTP Budi WTP Rama WTP Togar WTP When Q = 1, the height of the demand curve is $300, which is Flea’s willingness to pay, or how much he values an iPod. At any price higher than $300, Flea leaves the market; hence, at Q = 1, Flea is the marginal buyer. When Q = 2, the height of the demand curve is $250, which is Anthony’s willingness to pay, or how much he values an iPod. At any price higher than $250, Anthony leaves the market; hence, at Q = 2, Anthony is the marginal buyer. And so forth. The lesson here is summarized in the text on the right side of the screen: At each Q, the height of the D curve tells you the marginal buyer’s willingness to pay, or how much that buyer values the good. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Surplus Konsumen (CS) CS = WTP – P Surplus Konsumen adalah kesediaan konsumen untuk membayar dikurangi harga sebenarnya (aktual) untuk barang tersebut: CS = WTP – P Katakanlah P = $260. CS (Jodi) = 300 – 260 = 40. Budi, Rama, dan Togar tidak mendapatkan CS karena mereka tidak akan membeli batik pada harga 260. Total CS = $40. Nama WTP Budi 250 Rama 175 Jodi 300 Togar 125 CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CS dan Kurva Demand P Q P = $260 CS Jodi = $300 – 260 = $40 Total CS = $40 Jodi WTP The area of any rectangle equals base times height. For the green rectangle on this slide, base = 1 height = $300 – 260 = $40 area = 1 x $40 = $40 Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CS dan Kurva Demand P Q Katakanlah, P = $220 CS Jodi = $300 – 220 = $80 CS Budi = $250 – 220 = $30 Total CS = $110 Jodi WTP Budi WTP The entire green area (total CS) can be divided into two rectangles: The first (and leftmost) represents Flea’s CS. It has a height of $80 and a width of 1. The second represents Anthony’s CS. It has a height of $30 and a width of 1. The sum of these two rectangular areas equals total CS. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CS dan Kurva Demand P Q lesson: Total CS sama dengan daerah dibawah kurva D dan diatas harga, dari 0 sampai Q. The text in the yellow box summarizes the lesson of the two preceding slides. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CS dengan Banyak Pembeli & Kurva D Smooth Q = 5(ribuan), marginal buyer adalah willing to pay $50 untuk sepasang sepatu. Katakanlah P = $30. maka consumer surplus = $20. P Q $ Permintaan untuk sepatu Harga sepasang sepatu D 1000 pasang sepatu In “normal” or edit mode, the text appears to overlap with the vertical axis label. Don’t worry – in “Slide Show” or presentation mode, the axis labels disappear before the text appears. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CS dengan Banyak Pembeli & Kurva D Smooth CS adalah daerah antara P dan kurva D , dari 0 ke Q. Recall: luas dari setiga sama dengan ½ x alas x tinggi Tinggi segitiga adalah $60 – 30 = $30. jadi, CS = ½ x 15 x $30 = $225. P Q Permintaan Sepatu $ h D I have found that some students mistake the upper vertical intercept ($60 in this example) for the height of the triangle: they forget to subtract off the height of the bottom of the triangle from the height of the top of the triangle. So, the first one or two times, it might be worthwhile to show them how to find the height of the triangle. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Bagaimana Harga yang lebih tinggi mengurangi CS jika P meningkat menjadi $40, CS = ½ x 10 x $20 = $100 Dua konsekuensi turunnya CS. P Q 1. Turunnya CS menyebabkan pembeli meninggalkan pasar D 2. Turunnya CS menyebabkan tersisanya pembeli yang membeli dengan P lebih tinggi The book shows how a lower price increases CS. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

A C T I V E L E A R N I N G 1: Consumer surplus Kurva Demand P $ A. Temukan marginal buyer’s WTP pada Q = 10. B. temukan CS untuk P = $30. Katakanlah P turun menjadi $20. Berapa banyak CS akan meningkat karena… C. Pembeli masuk ke pasar D. Kehadiran pembeli yang membayar harga lebih rendah Q 16

A C T I V E L E A R N I N G 1: Answers demand curve P A. Q = 10, marginal buyer’s WTP adalah $30. B. CS = ½ x 10 x $10 = $50 $ P turun menjadi $20. C. CS untuk tambahan pembeli = ½ x 10 x $10 = $50 D. Peningkatan CS 10 units (dari awal) = 10 x $10 = $100 Q 17

Biaya dan Kurva Supply Cost adalah suatu nilai tertentu yang penjual hadapi untuk menghasilkan barang ( i.e., opportunity cost). Termasuk biaya dari semua sumber daya yang digunakan untuk menghasilkan barang, (sampai kepada nilai waktu yang dimiliki penjual). Contoh: biaya dari 3 penjual dalam bisnis angkringan. Penjual hanya akan berproduksi dan menjual barang jika harga barang melebihi dari biayanya. Maka dari itu, biaya adalah ukuran dari willingness to sell. Nama Biaya Andi $10 Rudi 20 Ratna 35 The material on cost, producer surplus, and the supply curve is analogous to the material earlier on WTP, consumer surplus, and the demand curve. Therefore, this section has a bit less detail here and should move a little more quickly. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Biaya dan Kurva Supply P Qs Daftar kuantitas penawaran dari data biaya yang tersedia: $0 – 9 10 – 19 1 20 – 34 2 Nama Biaya Andi $10 Rudi 20 Ratna 35 35 keatas 3 Your students should be able to figure out how to get the Qs numbers in the second column of the table. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Biaya dan Kurva Supply P Q P Qs $0 – 9 10 – 19 1 20 – 34 2 35 & up 3 10 – 19 1 20 – 34 2 35 & up 3 The derivation of the staircase-supply curve is analogous to that of the staircase demand curve in the earlier example. Hence, the animation is not as detailed. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Biaya dan Kurva Supply P Q Pada setiap Q, tinggi dari kurva S adalah biaya dari marginal seller, penjual akan meninggalkan pasar jika harga lebih rendah dari biayanya. Ratna cost Rudi cost For your students’ future reference, you might also note that we can use the term “marginal cost” as short-hand for “cost of the marginal seller.” Andi cost Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Surplus Produsen P Q PS = P – cost Surplus Produsen (PS): harga yang diterima penjual untuk suatu barang dikurangi biaya dalam memproduksi barang tersebut. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Surplus Produsen dan Kurva S PS = P – cost katakanlah P = $25. Andi PS = $15 Rudi PS = $5 Ratna PS = $0 Total PS = $20 Ratna cost Rudi cost Andi cost Total PS sama dengan daerah diatas kurva supply dan dibawah harga, dari 0 sampai Q. Q CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

PS Dengan Banyak Penjual & Kurva S Smooth Katakanlah P = $40 Pada Q = 15(ribuan), biaya marginal dari penjual adalah $30, dan surplus produsen adalah $10. P Q Supply sepatu harga sepasang sepatu S 1000 pasang sepatu CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

PS Dengan Banyak Penjual & Kurva S Smooth PS adalah daerah antara P dan kurva S, dari 0 sampai Q. Tinggi dari segitiga ini adalah $40 – 15 = $25. maka, PS = ½ x a x t = ½ x 25 x $25 = $312.5 P Q Supply sepatu S t CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Harga Lebih Rendah Mengurangi PS Jika P turun menjadi $30, PS = ½ x 15 x $15 = $112.5 Dua konsekuensi untuk turunnya PS. 1. Turunnya PS menyebabkan penjual meninggalkan pasar P Q S 2. Turunnya PS menyebabkan tersisanya penjual yang mendapatkan harga lebih rendah CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

A C T I V E L E A R N I N G 2: Producer Surplus Kurva supply P A. Temukan biaya marginal dari penjual pada Q = 10. B. Temukan PS untuk P = $20. katakanlah P meningkat menjadi $30. cari peningkatan PS karena C. menjual 5 unit tambahan D. Mendapatkan harga yang lebih tinggi dari 10 unit awal Q 27

A C T I V E L E A R N I N G 2: Answers supply curve P A. Pada Q = 10, marginal cost = $20 B. PS = ½ x 10 x $20 = $100 P meningkat $30. C. PS karena ada tambahan 5 unit = ½ x 5 x $10 = $25 D. kenaikan PS dari harga yang lebih tinggi dari10 unit awal = 10 x $10 = $100 Q 28

What do CS, PS, and Total Surplus Measure? CS = (value to buyers) – (amount paid by buyers) CS mengukur keuntungan yang diterima pembeli dari partisipasinya di pasar. PS = (amount received by sellers) – (cost to sellers) PS mengukur keuntungan yang diterima penjual dari partisipasi pasar. Total surplus = CS + PS TS mengukur total keuntungan dari perdagangan di pasar. It might help to say “participating in the market” means buying and selling. It might also help to say that CS measures the net benefit to buyers: the value they get from the good is the gross benefit, minus what they pay leaves the net benefit, or CS. Similarly, PS is the net benefit to sellers. I did not put “net benefit” on this slide because it is not in the book. But if you wish, you may add it. After showing this slide in class, I show my students a short scene from the movie “Pretty Woman” as an example of these concepts. In this scene, Julia Roberts is taking a bubble bath in Richard Gere’s hotel room (don’t worry – there’s no nudity!). Gere comes into the bathroom and they negotiate a price for her to “be at his beck and call” for a week. After bargaining for a few seconds, they agree on a price of $3000. A minute later, he says he would have paid $4000 (his willingness to pay), and she said she would have accepted $2000 (her “cost”). From this, we can deduce that CS = $1000, PS = $1000, and total surplus = $2000. If this transaction did not occur, then these characters would not have received these “gains from trade.” Disclaimer: We officially urge you to consult with your institution’s legal advisor to verify that showing this brief clip in your class does not violate any copyright laws. We accept no responsibility in this matter. For example, we absolutely do not recommend that you rent “Pretty Woman” on DVD, download a free evaluation copy of a program like AoA DVD Ripper from the website www.aoamedia.com, and use that software to create a video clip of the above-described segment of Pretty Woman from the DVD, a video clip which could then be moved to the computer in your classroom to be shown in your classroom presentation of this chapter. We urge you to respect the intellectual property of others, and all copyright laws. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

The Market’s Allocation of Resources Dalam pasar, alokasi sumber daya decentralized, ditentukan melalui interaksi dari banyak kepentingan pembeli dan penjual. Apakah alokasi sumber daya menjadi sesuatu yang diinginkan? Atau akankah alokasi sumber daya yang berbeda membuat masyarakat lebih baik? Untuk menjawab, kita menggunakan total surplus sebagai ukuran dari kesejahteraan masyarakat. Is the market’s allocation of resources desirable? This question is important, because the answer to it has implications for the proper role and scope of government. If the market’s allocation is generally desirable, then the role of government should be limited to the protection of property rights, national defense and so forth. If not, then public policy may potentially be able to improve upon the market’s allocation. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Mengukur Kesejahteraan Masyarakat Total surplus = CS + PS = (value to buyers) – (amount paid by buyers) + (amount received by sellers) – (cost to sellers) = (value to buyers) – (cost to sellers) CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Efficiency Total surplus = (value to buyers) – (cost to sellers) Alokasi sumber daya efisien jika alokasi tersebut memaksimalkan total surplus. Efisiensi artinya: Menaikan atau menurunkan kuantitas dari barang tidak akan meningkatkan total surplus. Barang-barang yang diproduksi oleh produsen diproduksi dengan biaya yang terendah. Barang yang dikonsumsi oleh pembeli adalah barang dengan nilai paling tinggi. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Efficiency Total surplus = (value to buyers) – (cost to sellers) Efficiency means making the pie as big as possible. berlawanan, equity mengarah pada apakah pie dibagi secara adil. Apakah “adil” subjektif, sulit untuk dievaluasi. Sebab itu, kita akan fokus pada efisiensi sebagai tujuan, meskipun pembuat kebijakan dalam dunia nyata biasanya peduli dengan equity. If you are pressed for time, this slide can be omitted without loss of continuity. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Evaluating the Market Equilibrium Market eq’m: P = $30 Q = 15,000 Total surplus = CS + PS Apakah equilibrium pasar efisien? P Q D CS S PS CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Which Buyers Get to Consume the Good? Tiap pembeli dengan WTP ≥ $30 akan membeli. pembeli dengan WTP < $30 tidak akan membeli. Maka, pembeli yang menilai barang dengan sangat tinggi adalah orang yang mengkonsumsi barang tsb. P Q D S It may be worth reminding your students that, at each Q, the height of the D curve is the marginal buyer’s valuation of the good. Hence, the buyers from 0 to 15 all value the good at least as much as the price, so they will purchase the good at the market price. The buyers from 15 on up value the good less than $30, so they won’t buy the good. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Which Sellers Produce the Good? Tiap penjual dengan biaya≤ $30 akan memproduksi barang. Tiap penjual dengan biaya> $30 tidak akan produksi. sebab itu, penjual dengan biaya terendah akan memproduksi barang. P Q D S Because the height of the S curve tells us seller’s costs, we can determine the following: The sellers of the first 15 units have cost < $30, so it is worthwhile for them to produce the good. The other sellers have cost > $30, so they will not sell the good if P = $30. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Does Eq’m Q Maximize Total Surplus? Pada Q = 20, biaya dari producing marginal unit adalah $35 value to consumers marginal unit adalah $20 Sebab itu, dapat meningkatkan total surplus melalui pengurangan Q. Hal ini benar pada Q yang lebih besar dari 15. P Q D S This slide shows that, if we are starting from a Q greater than the market equilibrium quantity, we can increase total surplus by reducing Q. The slide demonstrates this for one particular Q (20), but it is true for any Q greater than the equilibrium quantity. Thus, if we continue to reduce Q, total surplus will continue to increase – until we get to the equilibrium quantity. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Does Eq’m Q Maximize Total Surplus? pada Q = 10, biaya dari producing marginal unit adalah $25 value to consumers of the marginal unit adalah $40 Sebab itu, dapat meningkatkan total surplus melalui peningkatanQ. Hal ini benar pada tingkat Q kurang dari 15. P Q D S This slide shows that, if we are starting from a Q less than the market equilibrium quantity, we can increase total surplus by increasing Q. The slide demonstrates this for one particular Q (10), but it is true for any Q below the equilibrium quantity. Thus, if we continue to increase Q, total surplus will continue to increase – until we get to the equilibrium quantity. The lesson of these two slides: The equilibrium quantity maximizes total surplus. At any other quantity, total surplus is smaller than at the equilibrium quantity. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Evaluating the Market Eq’m: Summary The market eq’m is efficient: Equilibrium Q memaksimalkan total surplus. Barang yang dihasilkan oleh produsen dengan biaya paling rendah, Dan dikosumsi oleh pembeli yang menilai barang tersebut dengan sangat tinggi. Pemerintah tidak dapat menaikan market outcome. Laissez faire (French for “allow them to do”): the govt should not interfere with the market. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Why Non-Market Allocations Are Usually Bad Misalkan alokasi sumber daya ditentukan oleh central planner (e.g., the Communist leaders of the former Soviet Union.) Untuk memilih alokasi yang efisien, pembuat rencana perlu mengetahui tiap biaya yang dihadapi penjual dan WTP dari pembeli, untuk setiap ribuan barang yang diproduksi dalam perekonomian. Secara praktis hal ini tidak mungkin, sehingga tidak akan pernah efisien. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Adam Smith and the Invisible Hand Passages from The Wealth of Nations, 1776 “Man has almost constant occasion for the help of his brethren, and it is vain for him to expect it from their benevolence only. He will be more likely to prevail if he can interest their self-love in his favor, and show them that it is for their own advantage to do for him what he requires of them… This and the following slide contain passages from The Wealth of Nations. It would be hard to overstate the impact of the ideas in these passages. I have included them here, because students should be able to better understand and appreciate their significance after having just seen the analysis of market efficiency. If you’re pressed for time, you might delete the first of these two slides, as it is probably less important than the second one. The passages on this first slide convey the sense that the economy is made up of a completely uncoordinated mass of individuals, each acting in his or her own self interest. On the next slide, Smith discusses the invisible hand. It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest…. Adam Smith, 1723-1790 CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Adam Smith and the Invisible Hand Passages from The Wealth of Nations, 1776 “Every individual…neither intends to promote the public interest, nor knows how much he is promoting it…. He intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part of his intention. an invisible hand Nor is it always the worse for the society that it was no part of it. By pursuing his own interest he frequently promotes that of the society more effectually than when he really intends to promote it.” Adam Smith, 1723-1790 CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CONCLUSION Bab ini menggunakan ekonomi kesejahteraan untuk mendemonstrasikan satu dari Ten Principles: Markets are usually a good way to organize economic activity. Tapi kita mengasumsikan pasar adalah persaingan sempurna. Di dunia nyata, kadang terjadi market failures, ketika pasar yang tidak diatur gagal untuk mengalokasi sumber daya secara efisien. penyebab: market power – satu pembeli atau penjual dapat mempengaruhi harga pasar, e.g. monopoly externalities – efek samping dari transaksi, e.g. pollution The three boldface purple terms on this slide were introduced in chapter 1 and will be defined more carefully in later chapters. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

CONCLUSION Ketika pasar gagal, kebijakan publik dapat memperbaiki masalah dan meningkatkan efisiensi. Kesejahteraan masyarakat dapat dilihat dari kegagalan pasar dan kebijakan pemerintah. Despite the possibility of market failure, the assumptions in this chapter work well in many markets, and the invisible hand remains extremely important. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Ringkasan Tinggi dari kurva D merefleksikan nilai barang dari pembeli— willingness to pay pembeli untuk barang tersebut. Consumer surplus adalah perbedaan antara kesediaan pembeli untuk membayar suatu barang dan harga aktual. Pada grafik, consumer surplus adalah daerah antara P dan kurva D . CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Ringkasan Tinggi dari kurva S adalah biaya dari penjual dalam memproduksikan barang. Penjual akan bersedia menjual jika harga yang mereka dapat adalah paling tidak sama besar dengan biaya produksi mereka. Producer surplus adalah perbedaan antara harga yang diterima penjual untuk suatu barang dan biaya dalam memproduksi barang tersebut. Pada grafik, producer surplus adalah daerah antara P dan kurva S. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS

Ringkasan Untuk mengukur kesejahteraan masyarakat, kita menggunakan, penjumlahan dari consumer dan producer surplus. Efisiensi berarti bahwa total surplus telah maksimum, dimana barang yang diproduksi oleh penjual diproduksi dengan biaya terendah, dan pembeli yang mengkonsumsi barang tersebut memberikan nilai yang paling tinggi. Dibawah persaingan sempurna, market outcome adalah efisien. Mengubah market outcome akan mengurangi total surplus. CHAPTER 7 CONSUMERS, PRODUCERS, EFFICIENCY OF MARKETS