14 Perusahaan di Pasar Kompetitif P R I N C I P L E S O F Perusahaan di Pasar Kompetitif 14 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 Having introduced the cost concepts in the previous chapter, we now begin to use those concepts to see how firms making production and pricing decisions in different market structures. In this chapter, we explore firm behavior under perfect competition. The next chapter covers the other extreme end of the competition spectrum – monopoly. The following two chapters cover the intermediate cases – oligopoly and monopolistic competition, respectively.

Di bab ini, kita akan melihat jawaban akan pertanyaan berikut ini Di bab ini, kita akan melihat jawaban akan pertanyaan berikut ini Apa yang dimaksud dengan pasar kompetitif? Apa yang dimaksud dengan nilai marginal? Bagaimana ini berhubungan dengan pendapatan total dan rata-rata? Bagaimana pasar kompetitif menentukan jumlah dari profit maksimum? Kapan perusahaan kompetitif tutup pada jangka pendek? Keluar dari pasar dalam jangka panjang? Bagaimana kurva pasar terlihat dalam jangka pendek dan jangka panjang? CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Pengantar: Skenario Tiga tahun setelah lulus, kamu menjalankan bisnis sendiri. Kamu telah memilih berapa banyak untuk diproduksi, berapa harga yang ditetapkan dan berapa banyak pekerja yang diperkerjakan. Faktor apa yang seharusnya mempengaruhi keputusan ini? Biaya anda (yang dipelajari dalam bab sebelumnya) Berapa banyak kompetisi yang dihadapi? Kita mulai mempelajari sikap di perusahaan di pasar kompetitif sempurna CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Karakteristik dari Persaingan Sempurna 1. Banyak pembeli dan penjual 2. Barang yang ditawarkan untuk dijual sebagian besar sama. 3. Perusahaan dapat bebas untuk masuk dan keluar pasar. Pada point 1 dan 2, tiap pembeli dan penjual adalah “price taker”-maka menerima harga yang diberikan “Firms can freely enter or exit the market” means there are no barriers or impediments to entry or exit. E.g., the government does not restrict the number of firms in the market. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Pendapatan di Perusahaan Kompetitif Total revenue (TR) Average revenue (AR) Marginal Revenue (MR): Perubahan TR dari menjual tambahan satu unit TR = P x Q TR Q AR = = P ∆TR ∆Q MR = These revenue concepts are analogous to the cost concepts (TC, ATC, MC) in the previous chapter. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

A C T I V E L E A R N I N G 1: Exercise Isilah kotak kosong dari tabel Q P TR AR MR $10 n.a. 1 $10 $10 2 $10 This easy exercise requires students to apply the definitions from the previous slide. It also demonstrates that MR = P for a competitive firm. (The table in this exercise is similar to Table 1 in the chapter.) 3 $10 4 $10 $40 $10 5 $10 $50 5

A C T I V E L E A R N I N G 1: Answers Isilah kotak kosong dari tabel Q P TR = P x Q TR Q AR = ∆TR ∆Q MR = $10 $30 $20 $10 $0 n.a. Notice that MR = P $10 1 $10 $10 2 $10 $10 3 $10 4 $10 $40 $10 5 $10 $50 6

MR = P untuk Pasar Sempurna Perusahaan kompetitif dapat meningkatkan outputnya tanpa mempengaruhi harga pasar Jadi, setiap penngkatan di Q akan menyebabkan pendapatan akan meningkat oleh P, i.e., MR = P. MR = P hanya benar jika perusahaan di pasar kompetitif CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Maksimisasi Profit Apakah Q memaksimalkan profit perusahaan? Apakah Q memaksimalkan profit perusahaan? Untuk menemukan jawaban, “Berpikirlah pada margin” Jika peningkatan Q pada satu unit, pendapatan meningkat dengan MR, biaya meningkat dengan MC Jika MR > MC, maka peningkatan Q akan meningkatka profit Jika MR < MC, maka mengurangi Q untuk meningkatkan profit CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Profit Maximization Profit = MR – MC (continued from earlier exercise) Q TR TC Profit MR MC Profit = MR – MC At any Q with MR > MC, increasing Q raises profit. $0 45 33 23 15 9 $5 5 7 1 –$5 $10 12 10 8 6 $4 –2 2 4 $6 1 10 10 2 20 At any Q with MR < MC, reducing Q raises profit. 10 (The table on this slide is similar to Table 2 in the textbook.) For most students, seeing the complete table all at once is too much information. So, the table is animated as follows: Initially, the only columns displayed are the ones students saw at the end of the exercise in Active Learning 1: Q, TR, and MR. Then, TC appears, followed by MC. It might be useful to remind students of the relationship between MC and TC. Then, the Profit column appears. Students should be able to see that, at each value of Q, profit equals TR minus TC. The last column to appear is the change in profit. When the table is complete, we use it to show it is profitable to increase production whenever MR > MC, such as at Q = 0 , 1, or 2. it is profitable to reduce production whenever MC > MR, such as at Q = 5. 3 30 10 4 40 10 5 50 CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

MC dan Firm’s Supply Decision Rule: MR = MC pada Q yang maksimum profit. Pada Qa, MC < MR. Jadi, peingkatan Q meningkatkan profit Pada Qb, MC > MR. Jadi, penurunan Q untuk meningkatkan profit. Pada Q1, MC = MR. merubah Q akan menurunkan profit Q Costs MC Qb P1 MR Qa Q1 This slide is similar to Figure 1 in the chapter. I’ve omitted the AVC and ATC curves (which appear in Figure 1 in the chapter) because they are not needed at this point. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

MC dan the Firm’s Supply Decision Jika harga meningkat pada P2, Maka jumlah yang profit-maximizing akan meningkatkan Q2. Kurva MC Menentukan Q perusahaan pada harga berapapun Costs MC P2 MR2 Q2 P1 MR Q1 Q Kurva MC adalah kurva supply perusahaan CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Shutdown vs. Exit Shutdown: Keputusan jangka pendel untuk tidak memproduksi apapun karena kondisi pasar Exit: Keputusan jangka panjang untuk meninggalkan pasar. Perusahaan yang shuts down sementara harus membayar biaya tetap. Perusahaan yang keluar dari pasar tidak harus membayar biaya apapun, baik fxe ataupun variabel. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Keputusan jangka pendek perusahaan untuk Shut Down Jika perusahaan shut down sementara, Pendapatan turun sebanyak TR Biata jatuh oleh VC Jadi, perusahaan harus shut down jika TR < VC. Membagi dua sisi oleh Q: TR/Q < VC/Q Jadi kita bisa menulis keputusan perusahaan seperti ini The “cost” of shutting down is TR, the revenue the firm loses if it shuts down. The “benefit” of shutting down is VC, because the firm doesn’t have to pay its variable costs if it shuts down. (It still must pay its FC, though.) If the benefit of shutting down exceeds the cost, it’s worthwhile for the firm to shut down. Shut down if P < AVC CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

A Competitive Firm’s SR Supply Curve Kurva penawaran Jangka Pendek perusahaan adalah bagian kuva MC diatas AVC Q Costs AVC Jika P > AVC, maka perusaa MC ATC In edit mode, it looks like the text boxes are on top of each other. But in presentation mode, the text boxes display only one at a time. Jika P < AVC, maka perusahaan shut downs(produces Q = 0). CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Ketidak relevanan Sunk Costs Sunk cost: Biaya yang telah dikomitmetkan dan tidak bisa dipulihkan Sunk costs harusnya tidak relevan dengan keputusan, anda harus membayar apapun keputusannya. FC adalah sunk cost: Perusahaan harus membayar biaya-biaya tetap walaupun produksi sgut downs. Jadi, FC tidak bermasalah dalam keputusan untuk shut down CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Keputusan perusahaan jangka panjang untuk keluar Jika perusahaan keluar dari pasar, Pendapata turun sebanyak TR Biaya turun sebanyak TC Jadi, perusahaan harus exit, jika TR<TC. Membagi masin-masing sisi dengan Q yntuk menulis kembali keputusan perusahaan dengan The “cost” of exiting is TR, the revenue the firm loses if it leaves the market. The “benefit” of exiting is TC, because the firm no longer pays its costs if it leaves the market. If the benefit of existing is greater than the cost, then it’s worthwhile for the firm to exit. Exit jika P < ATC CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

A New Firm’s Decision to Enter Market In the long run, a new firm will enter the market if it is profitable to do so: if TR > TC. Divide both sides by Q to express the firm’s entry decision as: Enter if P > ATC Similarly, a prospective entrant compares the benefits of entering the market (TR) with the costs (TC), and enters if the benefits exceed the costs. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Kurva Penawaran Perusahaan Kompetitif Kurva Penawaran jangka Panjang adalah bagian dari kurva MC diatas LRATC. Q Costs MC LRATC CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

A C T I V E L E A R N I N G 2A: Mengidentifikasi Profit Perusahaan Perusahaan Kompetitif Menentukan Profit total perusahaan, Menentujan area pada grafik yang menunjukkan profit perusahaan Q Costs, P MC ATC P = $10 MR 50 $6 Rather than tell students that profit equals (P – ATC) x Q, this exercise requires students to figure it out for themselves. If this exercise is too easy for your students, you can replace it with lecture slides that appear at the end of this file. 19

A C T I V E L E A R N I N G 2A: Answers Perusahaan Kompetitif Q Costs, P Profit per unit = P – ATC = $10 – 6 = $4 MC ATC P = $10 MR 50 profit $6 The height of the rectangle is P – ATC, profit per unit. The width of the rectangle is Q, the number of units. The area of the rectangle = height x width = (profit per unit) x (number of units) = total profit. Total profit = (P – ATC) x Q = $4 x 50 = $200 20

A C T I V E L E A R N I N G 2B: Identifying a firm’s loss A competitive firm Menentukan total kerugian perusahaan. Menentukan area dari gambar yang menunjukkan kerugian perusahaan. Q Costs, P MC ATC $5 30 Students that didn’t figure out the answer to the previous exercise should be able to get this one. If this exercise is too easy for your students, you can replace it with lecture slides that appear at the end of this file. P = $3 MR 21

A C T I V E L E A R N I N G 2B: Answers Perusahaan Kompetitif Q Costs, P MC Total Kerugian = (ATC – P) x Q = $2 x 30 = $60 ATC $5 30 loss loss per unit = $2 The height of the rectangle is ATC – P, loss per unit. The width of the rectangle is Q, the number of units. The area of the rectangle = height x width = (loss per unit) x (number of units) = total loss. MR P = $3 22

Asumsi: Market Supply 1) Semua perusahaan yang ada dan pendatang potensial mempunyai biaya yang identik. 2) Biaya setiap perusahaan tidak berubah saat perusahaan lain masuk atau keluar dari perusahaan. 3) Jumlah perusahaan di pasar adalah Tetap jika di short run (karenafixed costs) Variabel di long run (karena bebas masuk dan keluar) In the real world, there are many markets in which assumptions (1) and (2) do not hold. We make them here for simplicity. Later in the chapter, we will see how our results change if we drop either of these assumptions. Assumption (3) is more reasonable: In the real world, it is much easier for firms to enter or exit in the long run than in the short run. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Kurva Supply Pasar Jangka Pendek Selama PC > AVC, setiap perusahaan akan memproduksi jumlah yang profit maximizing, dimana MR=MC Melihat kembali bab 4: Pada tiap harga, jumlah yang ditawarkan pasar adalah jumlah kuantitas yang ditawarkan setiap perusahaan. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

The SR Market Supply Curve Example: 1000 identical firms. At each P, market Qs = 1000 x (one firm’s Qs) AVC One firm Q P (firm) Market Q P (market) MC S P3 P3 30 30,000 P2 P2 20 20,000 “Identical” means all firms have the same cost curves. Note: P1 is minimum AVC. At any price below P1, each firm will shut down, and market quantity supplied will equal zero. Hence, the market supply curve begins at price = P1 and Q = 10,000. P1 P1 10 10,000 CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Masuk dan Keluar di jangka panjang Dalam jangka panjang, jumlah perusahaan berubah kaena entry dan exit. Jika perusahaan yang ada memperoleh profit ekonomi yang positif, Perusahaan baru akan masuk. Suplly pasar jangka pendek bergeser ke kanan. P turun,mengurangi profit perusahaan. Pendatang berhenti saat profit ekonomi perusahaan telah mencapai 0 CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Entry & Exit in the Long Run Dalam jangka panjang, jumalh perusahaan akan berubah karena masuk dan keluar Jika perusahaan yang ada mengalami kerugian, Beberapa akan keluar dari pasar. Kurva supply jangka pendek bergeser ke kiri. P meningkat, mengurangi kerugaan perusahaan yang tersisa. Exit berhenti saat kerugian ekonomi perusahaan telah mencapai 0. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Kondisi Zero Profit Equilibrium Jangka Panjang : Proses masuknya atau keluar telah selesai- perusahaan yang tersisa memperoleh profit 0 Profit ekonomi yang 0 terjadi saat P = ATC. Karena perusahaan memproduksi saat P+MR=MC, kondisi zero-profit adalah P=MC=ATC Jadi MC akan berpotongan dengan ATC saat ATC minimum Dalam jangka panjang, P = minimum ATC. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

The LR Market Supply Curve Dalam jangka panjang, perusahaan umumnya memperoleh 0 Supply jangka panjang LR adalah horizontal pada P = minimum ATC. Satu Perusahaan Q P (firm) Pasar Q P (market) MC LRATC P = min. ATC That the LR market supply curve is horizontal at P = min ATC will become more clear shortly, when students see the SR and LR effects of an increase in demand. long-run supply CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Kenapa perusahaan tetapa di bisnis jika Profit = 0? Jika, profit ekonomi minus pada setiap biaya – termasuk biaya implisit, seperti biaya opportunitas dari waktu dan uang pemilik Pada equilibrium zero profit, perusahaan akan memperoleh pendapata yang cukup untuk menutupi biaya ini. Students often wonder why firms bother to stay in business if they make zero profit. The textbook gives a nice discussion of this, briefly summarized on this slide. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

SR & LR Effects dari peningkatan permintaan …tetapi peningkatan permintaan meningkatkan P,… Perusahaan memulai pada LR eq. Sepanjang waktu, profit mengundang pendatang, menggeser S ke kanan, mengurangi P... …membuat SR profit pada perusahaan …membuat keuntungnan nol dan meningkat pada eq. Jangka panjang One firm Market Q P (market) Q P (firm) S1 MC ATC S2 Profit D2 B P2 P2 Q2 D1 A C P1 long-run supply P1 This slide replicates Figure 8 from the textbook. In edit mode, the text boxes in the top part of the slide appear to be on top of each other. But in slide-show mode, the text boxes display one at a time. If students did not previously understand why the LR market supply curve is horizontal, this slide may help. Q1 Q3 CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

Kenapa kurva penawaran jangka panjang dapat berslope keatas The LR market supply curve horizontal jika 1) Semua perusahaan mempunyai biaya identik 2) Biaya tidak berubah saat perushaan lainnya masuk atau keluar dari pasar. Jika asumsi ini tidak benar, jika LR supply curve berslope keatas then LR supply curve slopes upward. Here are two of the assumptions we made previously, when we began the process of deriving the LR market supply curve. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

1) Firms Have Different Costs As P rises, firms with lower costs enter the market before those with higher costs. Further increases in P make it worthwhile for higher-cost firms to enter the market, which increases market quantity supplied. Hence, LR market supply curve slopes upward. At any P, For the marginal firm, P = minimum ATC and profit = 0. For lower-cost firms, profit > 0. The marginal firm is the firm that would exit the market if the price were any lower. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

2) Biaya meningkat saat perusahaan masuk di Pasar Di beberapa industri, supply dari input kunci terbatas In some industries, the supply of a key input is limited (e.g., terdapat jumlah tetap dari tanah yang susuai dari pertanian). Masuknya perusahaan baru meningkatkan permintaan dari input sehingga menyebabkan harga meningkat. Ini meningkatkan biaya semua perusahaan. Jika, peningkatan di P dibutuhkan untuk meningkatkan jumlah yang ditwarkan, jadi kurva oenawaran adalah upward-slopping. Another example: There’s a limited amount of beachfront property. An expansion of the beach resort industry will bid up the price of such property, and raises costs in the industry. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

KESIMPULAN: Efisiensi dari pasar kompetitif Profit-maximization: MC = MR Perfect competition: P = MR Jadi equilibrium kompetitif: P = MC Jika, MC adalah biaya untuk memproduksi unit tambahan P adalah nilai kepada pembeli dari tambahan unit. Jadi, equilibrium kompetitif adalah efisien,memaksimumkan total surplus. Jadi di bab selanjutnya, monopoly: pricing & production decisions, deadweight loss, regulation. Recall from Chapter 7: a competitive market equilibrium is efficient. This chapter has shown why: P = MR under perfect competition, so P = MC in the competitive market equilibrium. Reviewing these concepts now sets the stage for the next few chapters, where firms with market power set their price above marginal cost, leading to market inefficiencies and a potential role for government intervention. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

CHAPTER SUMMARY For a firm in a perfectly competitive market, price = marginal revenue = average revenue. If P > AVC, a firm maximizes profit by producing the quantity where MR = MC. If P < AVC, a firm will shut down in the short run. If P < ATC, a firm will exit in the long run. In the short run, entry is not possible, and an increase in demand increases firms’ profits. With free entry and exit, profits = 0 in the long run, and P = minimum ATC. CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

profit-maximizing quantity A Firm With Profits Costs, P MC revenue per unit = P MR Q profit ATC profit per unit = P – ATC cost per unit = ATC This slide is “hidden” and will not display in your presentation. I have included it here in case you would like to substitute it for “Active Learning 2A.” The height of the rectangle is P – ATC, profit per unit. The width of the rectangle is Q, the number of units. The area of the rectangle = height x width = (profit per unit) x (number of units) = total profit. Q profit-maximizing quantity CHAPTER 14 FIRMS IN COMPETITIVE MARKETS

loss-minimizing quantity A Firm With Losses Costs, P MC ATC cost per unit = ATC Q loss loss per unit This slide is “hidden” and will not display in your presentation. I have included it here in case you would like to substitute it for “Active Learning 2B.” The height of the rectangle is ATC – P, loss per unit. The width of the rectangle is Q, the number of units. The area of the rectangle = height x width = (loss per unit) x (number of units) = total loss. revenue per unit = P MR Q loss-minimizing quantity CHAPTER 14 FIRMS IN COMPETITIVE MARKETS