1. ©2005 Pearson Education, Inc. Chapter 81 0 5 10 15 20 25 101520253035404550 Distribution of Grades Midterm #2 Mean = 28.30 Median = 29

2. Chapter 8 Profit Maximization and Competitive Supply

3. ©2005 Pearson Education, Inc. Chapter 83 Perfectly Competitive Markets The model of perfect competition can be used to study a variety of markets Basic assumptions of Perfectly Competitive Markets 1.Price taking 2.Product homogeneity 3.Free entry and exit

4. ©2005 Pearson Education, Inc. Chapter 84 When are Markets Competitive? Few real products are perfectly competitive Many markets are, however, highly competitive  They face relatively low entry and exit costs  Highly elastic demand curves No rule of thumb to determine whether a market is close to perfectly competitive  Depends on how they behave in situations

5. ©2005 Pearson Education, Inc. Chapter 85 Profit Maximization Do firms maximize profits?  Managers in firms may be concerned with other objectives Revenue maximization Revenue growth Dividend maximization Short-run profit maximization (due to bonus or promotion incentive)  Could be at expense of long run profits

6. ©2005 Pearson Education, Inc. Chapter 86 Profit Maximization Implications of non-profit objective  Over the long run, investors would not support the company  Without profits, survival is unlikely in competitive industries Managers have constrained freedom to pursue goals other than long-run profit maximization

7. ©2005 Pearson Education, Inc. Chapter 87 Marginal Revenue, Marginal Cost, and Profit Maximization We can study profit maximizing output for any firm, whether perfectly competitive or not  Profit (  ) = Total Revenue - Total Cost  If q is output of the firm, then total revenue is price of the good times quantity  Total Revenue (R) = Pq

8. ©2005 Pearson Education, Inc. Chapter 88 Marginal Revenue, Marginal Cost, and Profit Maximization Costs of production depends on output  Total Cost (C) = C(q) Profit for the firm, , is difference between revenue and costs

9. ©2005 Pearson Education, Inc. Chapter 89 Profit Maximization – Short Run 0 Cost, Revenue, Profit ($s per year) Output C(q) R(q) A B  (q) q0q0 q* Profits are maximized where MR (slope at A) and MC (slope at B) are equal Profits are maximized where R(q) – C(q) is maximized

10. ©2005 Pearson Education, Inc. Chapter 810 Marginal Revenue, Marginal Cost, and Profit Maximization Profit is maximized at the point at which an additional increment to output leaves profit unchanged

11. ©2005 Pearson Education, Inc. Chapter 811 Marginal Revenue, Marginal Cost, and Profit Maximization The Competitive Firm  Price taker – market price and output determined from total market demand and supply  Market output (Q) and firm output (q)  Market demand (D) and firm demand (d)

12. ©2005 Pearson Education, Inc. Chapter 812 The Competitive Firm Demand curve faced by an individual firm is a horizontal line  Firm’s sales have no effect on market price Demand curve faced by whole market is downward sloping  Shows amount of goods all consumers will purchase at different prices

13. ©2005 Pearson Education, Inc. Chapter 813 The Competitive Firm d$4 Output (bushels) Price $ per bushel 100200 Firm Industry D $4 S Price $ per bushel Output (millions of bushels) 100

14. ©2005 Pearson Education, Inc. Chapter 814 The Competitive Firm The competitive firm’s demand  Individual producer sells all units for $4 regardless of that producer’s level of output  MR = P with the horizontal demand curve  For a perfectly competitive firm, profit maximizing output occurs when

15. ©2005 Pearson Education, Inc. Chapter 815 Choosing Output: Short Run In the short run, capital is fixed and firm must choose levels of variable inputs to maximize profits We can look at the graph of MR, MC, ATC and AVC to determine profits The point where MR = MC, the profit maximizing output is chosen

16. ©2005 Pearson Education, Inc. Chapter 816 q2q2 A Competitive Firm 10 20 30 40 Price 50 MC AVC ATC 01234567891011 Output q*q* AR=MR=P A q 1 : MR > MC q 2 : MC > MR q*: MC = MR q1q1 Lost Profit for q 2 >q* Lost Profit for q 1 < q*

17. ©2005 Pearson Education, Inc. Chapter 817 A Competitive Firm – Positive Profits 10 20 30 40 Price 50 01234567891011 Output q2q2 MC AVC ATC q*q* AR=MR=P A q1q1 D C B Profits are determined by output per unit times quantity Profit per unit = P- AC(q) = A to B Total Profit = ABCD

18. ©2005 Pearson Education, Inc. Chapter 818 The Competitive Firm A firm does not have to make profits It is possible a firm will incur losses if the P < AC for the profit maximizing quantity  Still measured by profit per unit times quantity  Profit per unit is negative (P – AC < 0)

19. ©2005 Pearson Education, Inc. Chapter 819 A Competitive Firm – Losses Price Output MC AVC ATC P = MR D At q * : MR = MC and P < ATC Losses = (P- AC) x q * or ABCD q*q* A B C

20. ©2005 Pearson Education, Inc. Chapter 820 Choosing Output in the Short Run Summary of Production Decisions  Profit is maximized when MC = MR  If P > ATC the firm is making profits  If P < ATC the firm is making losses

21. ©2005 Pearson Education, Inc. Chapter 821 Short Run Production Why would a firm produce at a loss?  Might think price will increase in near future  Shutting down and starting up could be costly Firm has two choices in short run  Continue producing  Shut down temporarily  Will compare profitability of both choices

22. ©2005 Pearson Education, Inc. Chapter 822 Short Run Production When should the firm shut down?  If AVC < P < ATC, the firm should continue producing in the short run Can cover all of its variable costs and some of its fixed costs  If AVC > P < ATC, the firm should shut down Cannot cover its variable costs or any of its fixed costs

23. ©2005 Pearson Education, Inc. Chapter 823 A Competitive Firm – Losses Price Output P < ATC but  AVC so firm will continue to produce in short run MC AVC ATC P = MR D q*q* A B C Losses E F

24. ©2005 Pearson Education, Inc. Chapter 824 Competitive Firm – Short Run Supply Supply curve tells how much output will be produced at different prices Competitive firms determine quantity to produce where P = MC  Firm shuts down when P < AVC Competitive firms’ supply curve is portion of the marginal cost curve above the AVC curve

25. ©2005 Pearson Education, Inc. Chapter 825 A Competitive Firm’s Short-Run Supply Curve Price ($ per unit) Output MC AVC ATC P = AVC P2P2 q2q2 The firm chooses the output level where P = MR = MC, as long as P > AVC. P1P1 q1q1 S Supply is MC above AVC

26. ©2005 Pearson Education, Inc. Chapter 826 MC 2 q2q2 Input cost increases and MC shifts to MC 2 and q falls to q 2. MC 1 q1q1 The Response of a Firm to a Change in Input Price Price ($ per unit) Output $5 Savings to the firm from reducing output

27. ©2005 Pearson Education, Inc. Chapter 827 Short-Run Market Supply Curve Shows the amount of product the whole market will produce at given prices Is the sum of all the individual producers in the market We can show graphically how we can sum the supply curves of individual producers

28. ©2005 Pearson Education, Inc. Chapter 828 MC 3 Industry Supply in the Short Run $ per unit MC 1 S The short-run industry supply curve is the horizontal summation of the supply curves of the firms. Q MC 2 1521 P1P1 P3P3 P2P2 108247 5

29. ©2005 Pearson Education, Inc. Chapter 829 Long-Run Competitive Equilibrium For long run equilibrium, firms must have no desire to enter or leave the industry Relate economic profit to the incentive to enter and exit the market Relate accounting profit to economic profit

30. ©2005 Pearson Education, Inc. Chapter 830 Long-Run Competitive Equilibrium Accounting profit  Difference between firm’s revenues and direct costs Economic profit  Difference between firm’s revenues and direct and indirect costs  Takes into account opportunity costs

31. ©2005 Pearson Education, Inc. Chapter 831 Long-Run Competitive Equilibrium Firm uses labor (L) and capital (K) with purchased capital Accounting Profit and Economic Profit  Accounting profit:  = R - wL  Economic profit:  = R = wL - rK wl = labor cost rk = opportunity cost of capital

32. ©2005 Pearson Education, Inc. Chapter 832 Long-Run Competitive Equilibrium Zero-Profit  A firm is earning a normal return on its investment  Doing as well as it could by investing its money elsewhere  Normal return is firm’s opportunity cost of using money to buy capital instead of investing elsewhere  Competitive market long run equilibrium

33. ©2005 Pearson Education, Inc. Chapter 833 Long-Run Competitive Equilibrium Zero Economic Profits  If R > wL + rk, economic profits are positive  If R = wL + rk, zero economic profits, but the firm is earning a normal rate of return, indicating the industry is competitive  If R < wl + rk, consider going out of business

34. ©2005 Pearson Education, Inc. Chapter 834 Long-Run Competitive Equilibrium Entry and Exit  The long-run response to short-run profits is to increase output and profits  Profits will attract other producers  More producers increase industry supply, which lowers the market price  This continues until there are no more profits to be gained in the market – zero economic profits

35. ©2005 Pearson Education, Inc. Chapter 835 Long-Run Competitive Equilibrium – Profits S1S1 Output $ per unit of output $ per unit of output LAC LMC D S2S2 $40P1P1 Q1Q1 FirmIndustry Q2Q2 P2P2 q2q2 $30 Profit attracts firms Supply increases until profit = 0

36. ©2005 Pearson Education, Inc. Chapter 836 Long-Run Competitive Equilibrium – Losses S2S2 Output $ per unit of output $ per unit of output LAC LMC D S1S1 P2P2 Q2Q2 FirmIndustry Q1Q1 P1P1 q2q2 $20 $30 Losses cause firms to leave Supply decreases until profit = 0

37. ©2005 Pearson Education, Inc. Chapter 837 Long-Run Competitive Equilibrium 1.All firms in industry are maximizing profits  MR = MC 2.No firm has incentive to enter or exit industry  Earning zero economic profits 3.Market is in equilibrium  Q D = Q S

38. ©2005 Pearson Education, Inc. Chapter 838 Choosing Output in the Long Run Economic Rent  The difference between what firms are willing to pay for an input less the minimum amount necessary to obtain it  When some have accounting profits that are larger than others, they still earn zero economic profits because of the willingness of other firms to use the factors of production that are in limited supply

39. ©2005 Pearson Education, Inc. Chapter 839 Choosing Output in the Long Run An Example  Two firms A & B that both own their land  A is located on a river which lowers A’s shipping cost by $10,000 compared to B  The demand for A’s river location will increase the price of A’s land to $10,000 = economic rent  Although economic rent has increased, economic profit has become zero

40. ©2005 Pearson Education, Inc. Chapter 840 Firms Earn Zero Profit in Long-Run Equilibrium Ticket Price Season Tickets Sales (millions)$7 1.0 A baseball team in a moderate-sized city sells enough tickets so that price is equal to marginal and average cost (profit = 0). LACLMC

41. ©2005 Pearson Education, Inc. Chapter 841 1.3 $10 Economic Rent Ticket Price$7.20 A team with the same cost in a larger city sells tickets for $10. Firms Earn Zero Profit in Long-Run Equilibrium Season Tickets Sales (millions) LACLMC

42. ©2005 Pearson Education, Inc. Chapter 842 Firms Earn Zero Profit in Long-Run Equilibrium With a fixed input such as a unique location, the difference between the cost of production (LAC = 7) and price ($10) is the value or opportunity cost of the input (location) and represents the economic rent from the input

43. ©2005 Pearson Education, Inc. Chapter 843 Firms Earn Zero Profit in Long-Run Equilibrium If the opportunity cost of the input (rent) is not taken into consideration, it may appear that economic profits exist in the long run (positive accounting profits)