Ch07_Pindyck生产成本

©2005 Pearson Education, Inc.
Chapter 7
7
Sunk Cost
Firm buys a piece of equipment that cannot be converted to another use专用 设备 Expenditure on the equipment is a sunk cost
∆VC ∆TC MC = = ∆q ∆q
©2005 Pearson Education, Inc. Chapter 7 14
平均成本
Average Total Cost (ATC)
Cost per unit of output Also equals average fixed cost (AFC) plus average variable cost (AVC)
©2005 Pearson Education, Inc. Chapter 7 9
Prospective Sunk Cost
Example (cont.) The first building should be purchased The $500,000 is a sunk cost and should not be considered in the decision to buy What should be considered is
©2005 Pearson Education, Inc. Chapter 7 8
Prospective Sunk Cost
An Example
Firm is considering moving its headquarters A firm paid $500,000 for an option to buy a building The cost of the building is $5 million for a total of $5.5 million The firm finds another building for $5.25 million Which building should the firm buy?
How are costs calculated here?
©2005 Pearson Education, Inc.
Chapter 7
4
Measuring Cost: Which Costs Matter?
Accounting Cost会计成本 会计成本 实际发生的费用和固定资产的折旧 Economic Cost经济成本 经济成本 企业在生产中所使用的资源的成本
©2005 Pearson Education, Inc.
Chapter 7
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Cost in the Long Run
如果场上没有购买飞机则可以将资本 存银行获得利息收入 $150 million 这是机会成本
8 9 10 11 12
13 Output
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©2005 Pearson Education, Inc.
Chapter 7
7.3长期成本 长期成本
长期内厂商能改变所有投入要素，因 长期内厂商能改变所有投入要素， 而改变规模 为了实现成本最小化， 为了实现成本最小化，厂商需要选择 合适的投入要素组合
Chapter 7
6
Measuring Cost: Which Costs Matter?
Although opportunity costs are hidden and should be taken into account, sunk costs should not Sunk Cost沉没成本 沉没成本 已经发生但无法收回的支出 在制定未来经济决策时应当忽略它。 在制定未来经济决策时应当忽略它
TC ATC = = AFC + AVC q TC TFC TVC ATC = = + q q q
©2005 Pearson Education, Inc. Chapter 7 15
7.2短期成本 短期成本
©2005 Pearson Education, Inc.
Chapter 7
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短期成本的决定因素 – An xample
Chapter 7
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固定成本与沉没成本
他们经常被混淆 Fixed Cost 在企业经营中必须支付的成本， 在企业经营中必须支付的成本，与产出 水平无关 影响企业决策 Sunk Cost 已经发生无法收回的成本。 已经发生无法收回的成本。不影响决策 将沉淀成本按摊销方式处理。 将沉淀成本按摊销方式处理。不区分沉 淀成本和固定成本
FC
10 11 12 13 Output
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©2005 Pearson Education, Inc.
Chapter 7
Cost Curves
120 100 Cost ($/unit)
MC
80 60 40 20 0 0 2 4 6 Output (units/yr)
Chapter 7
ATC AVC AFC
©2005 Pearson Education, Inc.
Chapter 7
5
Measuring Cost: Which Costs Matter?
Opportunity cost机会成本 机会成本
企业未将资源用于其他可供选择的最佳用ucation, Inc.
P
400
TC VC
Its slope equals AVC The slope of a point 300 on VC or TC equals MC 200 Therefore, MC = AVC at 7 units of output 100 (point A)
1 2 3 4 5 6 7
A
FC
∆L 1 ∆ L for a 1 unit ∆ Q = = ∆Q M PL
©2005 Pearson Education, Inc.
Chapter 7
18
Determinants of Short Run Costs – An Example
w 所以 MC = MP L
短期内，边际成本等于变化的投入 短期内， 要素的价格除以其边际产量 较低的劳动边际产量(MPL)味着较高 较低的劳动边际产量 味着较高 的边际成本 (MC)。每当劳动的边际产 。 量降低时， 量降低时，边际成本上升
©2005 Pearson Education, Inc.
Chapter 7
3
5.1衡量成本 衡量成本
For a firm to minimize costs, we must clarify what is meant by costs and how to measure them
It is clear that if a firm has to rent equipment or buildings, the rent they pay is a cost What if a firm owns its own equipment or building?
TC= FC+ VC
©2005 Pearson Education, Inc. Chapter 7 11
Fixed and Variable Costs
什么成本是固定的，什么是可变的， 什么成本是固定的，什么是可变的，和时 间长短有关 在短期内大多数成本固定 长期内大多数成本可变
©2005 Pearson Education, Inc.
VC
200
Variable cost increases with production and the rate varies with increasing and decreasing returns.
100 50
0 1 2 3 4 5 6 7 8 9
Fixed cost does not vary with output
Has no alternative use so cost cannot be recovered – opportunity cost is zero Decision to buy the equipment might have been good or bad, but now does not matter
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©2005 Pearson Education, Inc.
Cost Curves
When MC is below AVC, AVC is falling When MC is above AVC, AVC is rising When MC is below ATC, ATC is falling When MC is above ATC, ATC is rising Therefore, MC crosses AVC and ATC at the minimums
©2005 Pearson Education, Inc. Chapter 7 13
边际成本
Marginal Cost (MC):
The cost of expanding output by one unit Fixed costs have no impact on marginal cost, so it can be written as:
Spending an additional $5,250,000 or Spending an additional $5,000,000
©2005 Pearson Education, Inc.
Chapter 7
10
Measuring Cost: Which Costs Matter?
总成本包括: 总成本包括 1. Fixed Cost固定成本 固定成本 Does not vary with the level of output 2. Variable Cost 可变成本 Cost that varies as output varies