第九章生产成本

1、The Costs of production 生产成本 Chapter 9 The Market Forces of Supply and Demand Supply and demand are the two words that economists use most often. Supply and demand are the forces that make market economies work. Modern microeconomics is about supply, demand, and market equilibrium. 供给与需求的市场力量 供给与需求是

2、经济学家最常用的两 个词。 供给与需求是使市场经济运行的力 量。 现代微观经济学就是研究供给、需 求与市场均衡的学科。 WHAT ARE COSTS? According to the Law of Supply: Firms are willing to produce and sell a greater quantity of a good when the price of the good is high. This results in a supply curve that slopes upward. 什么是成本? 根据供给规律: 当一种物品价格高时，厂商愿意 生产和销售的更多

3、。 这导致供给曲线向上倾斜。 WHAT ARE COSTS? The Firms Objective The economic goal of the firm is to maximize profits. 什么是成本? 企业的目标 企业的经济目标是利润最大化 Total Revenue,Total Cost,and profit 总收入、总成本与利润 uTotal Revenue 总收入 uThe amount that the firm receives for the sale of its output. 企业销售产品所得 uTotal Cost 总成本 uThe market va

4、lue of the inputs a firm uses in production. 企业用于生产的投入要素的市场价值。 A Firms Profit 公司利润 Profit is the firms total revenue minus its total cost. Profit = Total revenue - Total cost 利润总收入总成本 Costs as Opportunity Costs A firms cost of production includes all the opportunity costs of making its output of goo

5、ds and services. Explicit and Implicit Costs A firms cost of production include explicit costs and implicit costs. Explicit costs are input costs that require a direct outlay of money by the firm. Implicit costs are input costs that do not require an outlay of money by the firm. 成本是机会成本 一个企业的生产成本包括生

6、产物品与劳 务量的所有机会成本。 显性成本和隐性成本 一个企业的生产成本包括显性成本与隐性成 本。 显性成本 要求企业直接支付货币的投入要素 成本。 隐性成本不要求企业支付货币的投入要素成 本。 Economic Profit versus Accounting Profit uEconomists measure a firms economic profit as total revenue minus all the opportunity costs (explicit and implicit). uAccountants measure the accounting profit

7、as the firms total revenue minus only the firms explicit costs. In other words, they ignore the implicit costs. 经济利润与会计利润 u经济学家计量企业的经济利润，即企业 的总收益减去生产所销售物品和劳务的 所有机会成本（显性的和隐性的）。 u会计师计量企业的会计利润，即企业的 总收益减去企业的显性成本。 Economic Profit versus Accounting Profit 经济利润与会计利润 uWhen total revenue exceeds both explici

8、t and implicit costs, the firm earns economic profit. 当总收益大于显性成本和隐性成本时，企 业赚取经济利润。 uEconomic profit is smaller than accounting profit. 经济利润小于会计利润。 Economic Profit versus Accounting Profit Revenue Total opportunity costs How an Economist Views a Firm Explicit costs Economic profit Implicit costs Expli

9、cit costs Accounting profit How an Accountant Views a Firm Revenue 经济利润与会计利润 收入收入 所有机所有机 会成本会成本 经济学家如何看企业经济学家如何看企业 显性成本显性成本 经济利润经济利润 隐性成本隐性成本 显性成本显性成本 会计利润会计利润 会计师如何看企业会计师如何看企业 收入收入 Table 1 A Production Function and Total Cost: Hungry Helens Cookie Factory Copyright2004 South-Western 表1. 生产函数和总成本：亨格

10、瑞.海伦的糕点厂 工人数量工人数量产出产出劳动的边劳动的边 际产量际产量 工厂成本工厂成本工人成本工人成本投入总成投入总成 本本 0 1 2 0 50 90 50 40 $30 30 30 $0 10 20 $30 40 50 3 4 120 140 30 20 30 30 30 40 60 70 515010305080 The Production Function 生产函数 The production function shows the relationship between quantity of inputs used to make a good and the quanti

11、ty of output of that good. 生产函数用于生产一种物品的投 入量与该物品产量之间的关系。 Marginal Product 边际产量 The marginal product of any input in the production process is the increase in the quantity of output obtained from an additional unit of that input. 任何一种生产过程中的投入要素的边 际产量是指增加一个单位的该要素投 入所引起的产量增加。 Marginal Product 边际产量 Addi

12、tional input 投入增加量投入增加量 Additional output = Marginal product 边际产量边际产量 产出增加量产出增加量 Diminishing Marginal Product uDiminishing marginal product is the property whereby the marginal product of an input declines as the quantity of the input increases. uExample: As more and more workers are hired at a firm

13、, each additional worker contributes less and less to production because the firm has a limited amount of equipment. 边际产量递减 u边际产量递减 是指一种投入要素的边际产 量随着该要素投入量的增加而减少的特征。 u例子: 由于雇佣的工人越来越多，每个新雇 佣的工人对产量的贡献越来越小，这是因为 有限的设备数量不能将他的潜能发挥出来。 Figure 2 Hungry Helens Production Function Quantity of Output (cookies pe

14、r hour) 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 Number of Workers Hired 012345 Production function 图2.亨格瑞.海伦的生产函数 产量产量 (cookies per hour) 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 雇佣工人数量雇佣工人数量 012345 生产函数生产函数 Diminishing Marginal Product uThe slope of the production function meas

15、ures the marginal product of an input, such as a worker. uWhen the marginal product declines, the production function becomes flatter. 边际产量递减 u生产函数的斜率衡量了一种投入要素 （比如一个工人）的边际产量。 u随着工人数量增加，边际产量减少， 生产函数越来越平坦。 From the Production Function to the Total-Cost Curve uThe relationship between the quantity a fi

16、rm can produce and its costs determines pricing decisions. uThe total-cost curve shows this relationship graphically. 从生产函数到总成本曲线 u一个企业可能的生产量和它的成本 之间的关系决定了它的产品定价。 u用来说明生产产量和生产总成本之 间关系的图被称为总成本曲线。 Table 1 A Production Function and Total Cost: Hungry Helens Cookie Factory Copyright2004 South-Western 表1

17、.生产函数和总成本亨格瑞.海伦的糕点厂 工人数量工人数量产出产出劳动的边际劳动的边际 产量产量 工厂成本工厂成本工人成本工人成本投入总成投入总成 本本 0 1 2 0 50 90 50 40 $30 30 30 $0 10 20 $30 40 50 3 4 120 140 30 20 30 30 30 40 60 70 515010305080 Figure 3 Hungry Helens Total-Cost Curve 图3. 亨格瑞.海伦的总成本曲线 Total cost 总成本总成本 $80 70 60 50 40 30 20 10 Quantity of Output 产量产量 (c

18、ookies per hour) 020401401201008060 Total-cost Curve 总成本曲线总成本曲线 The Various Measures of Cost 成本的各种衡量 Costs of production may be divided into fixed costs and variable costs. 生产成本可以分为固定成本 和可变成本。 Fixed and Variable Costs uFixed costs are those costs that do not vary with the quantity of output produced

19、. uVariable costs are those costs that do change as the firm alters the quantity of output produced. 固定成本和变动成本 u固定成本 不随着产量变动而变动 的成本。 u可变成本 随着产量变动而变动的 成本。 Total Costs 总成本 uTotal Fixed Costs (TFC) 总固定成本 （ TFC ） uTotal Variable Costs (TVC) 总可变成本（TVC） uTotal Costs (TC) 总成本 (TC) TC = TFC + TVC Table 2 Th

20、e Various Measures of Cost: Thirsty Thelmas Lemonade Stand Copyright2004 South-Western Table 2 The Various Measures of Cost: Thirsty Thelmas Lemonade Stand QuantityTotal CostFixed CostVariable Cost 0$ 3.00$3.00$ 0.00 13.303.000.30 23.803.000.80 34.503.001.50 45.403.002.40 56.503.003.50 67.803.004.80

21、 79.303.006.30 811.003.008.00 912.903.009.90 1015.003.0012.00 表2. 成本的各种衡量：索斯蒂.特尔玛的柠檬水店 数量总成本固定成本可变成本 0$ 3.00$3.00$ 0.00 13.303.000.30 23.803.000.80 34.503.001.50 45.403.002.40 56.503.003.50 67.803.004.80 79.303.006.30 811.003.008.00 912.903.009.90 1015.003.0012.00 Average Costs 平均成本 uAverage costs c

22、an be determined by dividing the firms costs by the quantity of output produced. 平均成本：总成本除以产量。 uThe average cost is the cost of each typical unit of product. 平均成本是生产一个普通单位的成本。 Family of Average Costs 平均成本 uAverage Fixed Costs (AFC) 平均固定成本 (AFC) uAverage Variable Costs (AVC) 平均可变成本 (AVC) uAverage Tot

23、al Costs (ATC) 平均总成本 (ATC) ATC = AFC + AVC Family of Average Costs AFC = Fixed cost Quantity = FC Q AVC = Variable cost Quantity = VC Q ATC = Total cost Quantity = TC Q AFC = Fixed cost Quantity = FC Q AVC = Variable cost Quantity = VC Q ATC = Total cost Quantity = TC Q 平均成本 F C A F C= Q V C A V C=

24、Q T C A T C= Q 固定成本 平均固定成本（） 产量 变动成本 平均可变成本（） 产量 总成本 平均总成本（） 产量 $3.00 Table 2 The Various Measures of Cost: Thirsty Thelmas Lemonade Stand QuantityAFCAVCATC 0 1$0.30$3.30 21.500.401.90 31.000.501.50 40.750.601.35 50.600.701.30 60.500.801.30 70.430.901.33 80.381.001.38 90.331.101.43 100.301.201.50 $3

25、.00 表2. 成本的各种衡量：索斯蒂.特尔玛的柠檬水店 产量AFCAVCATC 0 1$0.30$3.30 21.500.401.90 31.000.501.50 40.750.601.35 50.600.701.30 60.500.801.30 70.430.901.33 80.381.001.38 90.331.101.43 100.301.201.50 Marginal Cost uMarginal cost (MC) measures the amount total cost rises when the firm increases production by one unit.

26、 uMarginal cost helps answer the following question: uHow much does it cost to produce an additional unit of output? 边际成本 u边际成本 (MC) 衡量额外一个单位 产量所引起的总成本的增加。 u边际成本帮助回答以下问题： u生产额外一个单位产量的成本是多少？ Marginal Cost Q TC = quantity) in (Change cost) total in (Change =MC 边际成本 () MC= () TC = Q 总成本变化 产量变化 Marginal

27、 Cost：Thirsty Thelmas Lemonade Stand QuantityTotal Cost Marginal Cost QuantityTotal Cost Marginal Cost 0$3.00 13.30$0.306$7.80$1.30 23.800.5079.301.50 34.500.70811.001.70 45.400.90912.901.90 56.501.101015.002.10 边际成本：索斯蒂.特尔玛的柠檬水店 产量 总成本 边际成本 产量 总成本 边际成本 0 $3.00 1 3.30 $0.30 6 $7.80 $1.30 2 3.80 0.50

28、 7 9.30 1.50 3 4.50 0.70 8 11.00 1.70 4 5.40 0.90 9 12.90 1.90 5 6.50 1.10 10 15.00 2.10 Figure 4 Thirsty Thelmas Total-Cost Curves Total Cost $15.00 14.00 13.00 12.00 11.00 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 Quantity of Output (glasses of lemonade per hour) 014327659810 Total-cost c

29、urve 图4. 索斯蒂.特尔玛的总成本曲线 总成本总成本 $15.00 14.00 13.00 12.00 11.00 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 产量产量 (每小时柠檬水杯数每小时柠檬水杯数) 014327659810 总成本曲线 Figure 5 Thirsty Thelmas Average-Cost and Marginal- Cost Curves Costs $3.50 3.25 3.00 2.75 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 Quan

30、tity of Output (glasses of lemonade per hour) 014327659810 MC ATC AVC AFC 图5. 索斯蒂.特尔玛的平均成本和边际成本曲线 成本成本 $3.50 3.25 3.00 2.75 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 产量产量 (每小时柠檬水杯数每小时柠檬水杯数) 014327659810 MC ATC AVC AFC Cost Curves and Their Shapes 成本曲线及其形状 Marginal cost rises with the amount

31、of output produced. 边际成本随着产量增加而上升。 Marginal cost 边际成本 uThis reflects the property of diminishing marginal product. 边际成本递增反映了边际产量递减的性质 Figure 5 Thirsty Thelmas Average-Cost and Marginal- Cost Curves Costs $3.50 3.25 3.00 2.75 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 Quantity of Output (glass

32、es of lemonade per hour) 014327659810 MC 图5. 索斯蒂.特尔玛的平均成本和边际成本曲线 成本成本 $3.50 3.25 3.00 2.75 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 产量产量 (每小时柠檬水杯数）每小时柠檬水杯数） 014327659810 MC Cost Curves and Their Shapes The average total-cost curve is U-shaped. uAt very low levels of output average total cos

33、t is high because fixed cost is spread over only a few units. uAverage total cost declines as output increases. uAverage total cost starts rising because average variable cost rises substantially. 成本曲线及其形状 平均总成本曲线 是 U型的。 u在产量水平极低时，平均总成本高，这是因 为固定成本只分摊在少数几个单位产品上。 u平均总成本随着产量增加而降低。 u当平均可变成本大幅度上升时，平均总成本

34、开始增加。 Cost Curves and Their Shapes 成本曲线及其形状 The bottom of the U-shape occurs at the quantity that minimizes average total cost. This quantity is sometimes called the efficient scale of the firm. 在使平均总成本最小的产量时，U型曲 线的底部就出现了。这种产量有时被称 为企业的有效规模。 Figure 5 Thirsty Thelmas Average-Cost and Marginal- Cost Cu

35、rves Costs $3.50 3.25 3.00 2.75 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 Quantity of Output (glasses of lemonade per hour) 014327659810 ATC 图5. 索斯蒂.特尔玛的平均成本和边际成本曲线 成本成本 $3.50 3.25 3.00 2.75 2.50 2.25 2.00 1.75 1.50 1.25 1.00 0.75 0.50 0.25 产量产量 (每小时柠檬水杯数每小时柠檬水杯数) 014327659810 ATC Relationsh

36、ip Between Marginal Cost and Average Total Cost uWhenever marginal cost is less than average total cost, average total cost is falling. uWhenever marginal cost is greater than average total cost, average total cost is rising. 边际成本和平均总成本之间的关系 u只要边际成本小于平均总成本，平 均总成本就下降。 u只要边际成本大于平均总成本，平 均总成本就上升。 Relati

37、onship Between Marginal Cost and Average Total Cost The marginal-cost curve crosses the average-total-cost curve at the efficient scale. uEfficient scale is the quantity that minimizes average total cost. 边际成本和平均总成本之间的关系 边际成本曲线与平均总成本曲线相 交于有效规模时。 u有效规模使平均总成本最小的产 量。 MC ATC Relationship Between Margina

38、l Cost and Average Total Cost $0.00 $0.50 $1.00 $1.50 $2.00 $2.50 $3.00 $3.50 024681012 Quantity of Output (glasses of lemonade per hour) Costs MC ATC 边际成本和平均总成本之间的关系 $0.00 $0.50 $1.00 $1.50 $2.00 $2.50 $3.00 $3.50 024681012 产量产量 (每小时柠檬水杯数每小时柠檬水杯数) 成本成本 边际成本边际成本 平均总成本平均总成本 Typical Cost Curves 典型的成本曲

39、线 It is now time to examine the relationships that exist between the different measures of cost. 现在讨论一下不同衡量方式的成本 之间的关系。 Big Bobs Cost Curves 大鲍伯的成本曲线 百吉圈产百吉圈产 量量总成本总成本固定成本固定成本 可变成本可变成本 平均固定平均固定 成本成本 平均可变平均可变 成本成本 平均总成平均总成 本本边际成本边际成本 0$2.00$2.00$0.00 1$3.00$2.00$1.00$2.00$1.00$3.00$1.00 2$3.80$2.00$1

40、.80$1.00$0.90$1.90$0.80 3$4.40$2.00$2.40$0.67$0.80$1.47$0.60 4$4.80$2.00$2.80$0.50$0.70$1.20$0.40 5$5.20$2.00$3.20$0.40$0.64$1.04$0.40 6$5.80$2.00$3.80$0.33$0.63$0.97$0.60 7$6.60$2.00$4.60$0.29$0.66$0.94$0.80 8$7.60$2.00$5.60$0.25$0.70$0.95$1.00 9$8.80$2.00$6.80$0.22$0.76$0.98$1.20 10$10.20$2.00$8.2

41、0$0.20$0.82$1.02$1.40 11$11.80$2.00$9.80$0.18$0.89$1.07$1.60 12$13.60$2.00$11.60$0.17$0.97$1.13$1.80 13$15.60$2.00$13.60$0.15$1.05$1.20$2.00 14$17.80$2.00$15.80$0.14$1.13$1.27$2.20 Figure 6 Big Bobs Cost Curves (a) Total-Cost Curve $18.00 16.00 14.00 12.00 10.00 8.00 6.00 4.00 Quantity of Output (ba

42、gels per hour) TC 4268141210 2.00 Total Cost 0 图6.大鲍伯的成本曲线 (a) 总成本曲线总成本曲线 $18.00 16.00 14.00 12.00 10.00 8.00 6.00 4.00 产量产量 (每小时百吉圈每小时百吉圈) TC 4268141210 2.00 总成本总成本 0 Figure 6 Big Bobs Cost Curves (b) Marginal- and Average-Cost Curves Quantity of Output (bagels per hour) Costs $3.00 2.50 2.00 1.50

43、1.00 0.50 04268141210 MC ATC AVC AFC 图6.大鲍伯的成本曲线 (b) 边际和平均成本曲线边际和平均成本曲线 成本成本 $3.00 2.50 2.00 1.50 1.00 0.50 04268141210 MC ATC AVC AFC 产量产量 (每小时百吉圈每小时百吉圈) Typical Cost Curves Three Important Properties of Cost Curves Marginal cost eventually rises with the quantity of output. The average-total-cost

44、curve is U-shaped. The marginal-cost curve crosses the average- total-cost curve at the minimum of average total cost. 典型的成本曲线 成本曲线的三个重要特征 随着产量增加，边际成本最终要上升。 平均总成本曲线是U型的。 边际成本曲线与平均总成本曲线在平均总 成本最低点相交。 COSTS IN THE SHORT RUN AND IN THE LONG RUN uFor many firms, the division of total costs between fixed

45、and variable costs depends on the time horizon being considered. uIn the short run some costs are fixed. uIn the long run fixed costs become variable costs. 短期与长期成本 u对许多企业来说，总成本分为固定和 可变成本取决于所考察的时间长短。 u在短期中一些成本是固定的。 u在长期中成本都是可变的。 COSTS IN THE SHORT RUN AND IN THE LONG RUN 短期与长期成本 Because many costs a

46、re fixed in the short run but variable in the long run, a firms long-run cost curves differ from its short- run cost curves. 由于许多成本在短期中是固定的，但在长期 中是可变的，所以企业的长期成本曲线不同 于其短期成本曲线。 Figure 7 Average Total Cost in the Short and Long Run Quantity of Cars per Day 0 Average Total Cost 1,200 $12,000 ATC in shor

47、t run with small factory ATC in short run with medium factory ATC in short run with large factory ATC in long run 图7. 短期与长期的平均成本 Copyright 2004 South-Western 每天汽车产量每天汽车产量 01,200 $12,000 小型工厂短期小型工厂短期 ATC 中型工厂短期中型工厂短期 ATC 大型工厂短期大型工厂短期 ATC 长期长期 ATC 平均总平均总 成本成本 Economies and Diseconomies of Scale uEcono

48、mies of scale occur when long-run average total cost declines as output increases. uDiseconomies of scale occur when long-run average total cost rises as output increases. uConstant returns to scale occur when long- run average total cost does not vary as output increases. 规模经济与规模不经济 u当长期平均总成本随着产量增加

49、而减少 时，可以说存在规模经济。 u当长期平均总成本随着产量增加而增加 时，可以说存在规模不经济。 u当长期平均总成本不随着产量变动而变 动时，可以说存在规模收益不变。 Figure 7 Average Total Cost in the Short and Long Run Quantity of Cars per Day 0 Average Total Cost 1,200 $12,000 1,000 10,000 Economies of scale ATC in short run with small factory ATC in short run with medium factory ATC in short run with large factory ATC in long run Diseconomies of scale Constant returns to scale 图7. 短期与长期的平均总成本 每天汽车产量每天汽车产量 01,200 $12,000 1,000 10,000 规模经济 小型工厂短期小型工厂短期 ATC 中型工厂短期中型工厂短期 ATC 大型工厂