微觀經(jīng)濟學成本分析課件

1、成本分析第7章成本的經(jīng)濟分析7.13短期 The short run: The period in which firms can adjust production only by changing variable factors such as materials and labor but cannot change fixed factors such as capital.4固定成本 Fixed costs are expenses that must be paid even if the firm produces zero output. A firms fixed cost

2、s, sometimes called “overhead” (企業(yè)一般管理費用) or “sunk costs” (沉沒成本), must be paid even if the firm produces no output, and they will not change if output changes.5變動成本 The cost related to variable factors is called variable cost (變動成本，可變成本). Variable costs are those which vary as output changes. By def

3、inition, VC begins at zero when q is zero.6總成本是可達到的最小成本 Total cost represents the lowest total dollar expense needed to produce each level of output q. 說明：與生產(chǎn)函數(shù)的處理類似，總成本也是指給定產(chǎn)量時的最小成本，目的是為了讓成本函數(shù)關系具有唯一性。7Totalcostin short run:in long run:TotalcostVariablecost=FixedcostVariablecost+8(1)(2)(3)(4)Quantit

4、yFixed costVariable costTotal cost=(2)+(3)qFC($)VC($)TC($)055055155308525555110355751304551051605551552106552252809邊際成本 The concept of marginal cost is one of the most essential in microeconomics. Marginal cost (MC) denotes the extra or additional cost of producing 1 extra unit of output.10一個有空座位的航空

5、公司的飛機，額外增加一個旅客的成本是很低的。但是，在炎熱的夏天，當所有的空調(diào)都開啟時，增加一份電的使用的成本是非常高的。11邊際成本的計算(1)(2)(3)OutputTotal costMarginal costQTC($)MC($)0551852110313041605210302520305012利用變動成本計算邊際成本(1)(2)(3)OutputTotal costMarginal costQTC($)MC($)0013025537541055155302520305013數(shù)學推導 為什么可以用變動成本來計算邊際成本：MC = TCq+1 TCq = (VCq+1FC) (VCqFC

6、)= VCq+1 VCq14總成本和邊際成本的關系15平均成本Average cost(or unit cost)=total costoutput=TCq=ACAveragefixed cost=fixed costoutput=FCq= AFCAveragevariable cost=variable costoutput=VCq= AVC16總成本、固定成本和變動成本Total costVariable costFixed costQuantityCost17平均成本和邊際成本QuantityAverage and marginal costMCACAVCAFC平均成本最小平均變動成本最

7、小18平均成本與邊際成本的關系成本產(chǎn)量邊際成本平均成本平均成本最低點邊際成本曲線自下而上穿越平均成本曲線的最低點。19平均成本邊際成本成本產(chǎn)量邊際成本平均成本16元2212元邊際成本平均成本,平均成本曲線隨著產(chǎn)量增加而向下。20平均成本AC, then AC is rising. If MC=AC, then AC is at its low point. If MCAVC, then AVC is rising. If MC=AVC, then AVC is at its low point. If MCAVC, then AVC is falling.= AVCqMCAVCqq1AVCq+

8、1QuantityAC and MCAC25 2 4 6 8 10 12 14 16 18 20 1 2 3 4 5 6 7 8 9 10 產(chǎn)量 成本 總成本變動成本邊際成本平均成本平均變動成本數(shù)值計算的例子固定成本26斜率和邊際成本的關系Tangent lineTotal cost curve1 unit of outputMarginal costaaTCMCQ27產(chǎn)量與成本之間的聯(lián)系 The cost curve for a firm depends very closely on the prices of inputs and the firms production functio

9、n. If you know factor prices and the production function, you can calculate the cost curve. 說明：一個企業(yè)對要素市場價格的影響可以忽略不計，因此，通常假定要素的價格給定。28從生產(chǎn)數(shù)據(jù)和投入成本導出成本(1)(2)(3)(4)(5)(6)Output(tons of wheat)Land(acres)Labor(workers)Rent($ per acre)Wage($ per worker)Total cost($)01005.555511065.55?210115.55110310155.5513

10、0410215.55160510315.55?610455.552808521029報酬遞減和U形成本曲線In the short run:30企業(yè)資源最優(yōu)配置標準 企業(yè)資源最優(yōu)配置標準企業(yè)資源最優(yōu)配置標準：最后一單位資源用于各項用途時帶來的收益相等。用途1用途2用途N用途3總資源總資源31等邊際原理的解釋用途1用途2用途N用途3總資源總資源追加10萬元+利潤5萬元追加10萬元+利潤8萬元 5.萬元8萬元3萬元移動10萬元邊際生產(chǎn)力遞減定律減少10萬元-利潤5.萬元減少10萬元-利潤8.萬元 32等邊際原理$1$1ABABMPMPPPThis gives you the marginal pr

11、oduct per dollar of output.Equimarginal Principle33最小成本規(guī)則To a given output:Marginal product of input APrice of input A=Marginal product of input BPrice of input B=34替代規(guī)則 If the price of one factor falls while all other factor prices remain the same, firms will profit by substituting the now-cheaper

12、factor for all the other factors.MP of LaborPrice of Labor=MP of CapitalPrice of Capital要素的收入35短期成本與長期成本的關系成本產(chǎn)量長期平均成本1 畝地2 畝地4 畝地3 畝地1 畝地更有利2 畝地更有利3 畝地更有利4 畝地更有利36規(guī)模經(jīng)濟與規(guī)模不經(jīng)濟成本產(chǎn)量長期平均成本規(guī)模經(jīng)濟產(chǎn)量增加使得產(chǎn)品平均成本降低規(guī)模不經(jīng)濟產(chǎn)量增加使得產(chǎn)品平均成本增大經(jīng)濟成本和企業(yè)會計7.238經(jīng)濟成本和會計成本 經(jīng)濟成本經(jīng)濟成本（economic cost）：投入生產(chǎn)的所有資源的機會成本。 會計成本（accounting

13、cost）：按照會計規(guī)則計算的成本 在會計帳面上顯示出來的經(jīng)濟成本稱為外顯（顯性）成本（explicit costs），在會計帳面上不能顯示出來的經(jīng)濟成本稱為內(nèi)含（隱性）成本（implicit costs）。39經(jīng)濟利潤 經(jīng)濟成本 = 外顯成本 + 內(nèi)含成本 = 機會成本 經(jīng)濟利潤經(jīng)濟利潤 = 銷售收益 經(jīng)濟成本 經(jīng)濟利潤是計入了所有使用的資源代價后的純收益。40 一個體飯館業(yè)主使用自己的店面， 1年盈利3萬元，這個3萬元稱之為會計利潤。 若不開飯館，在所有可選工作中最高可賺得2萬元，人力的經(jīng)濟成本就是2萬元。如果店面用于出租可以獲得1.5萬元租金，那么店面的經(jīng)濟成本就是1.5 萬元。 考慮到

14、經(jīng)濟成本后，這個個體飯館業(yè)主的經(jīng)濟利潤為0.5 萬元。41收益表(1) Net sales$250,000Less cost of goods sold:(2) Materials$50,000(3) Labor cost90,000(4) Miscellaneous operating costs10,000(5) Less overhead costs:(6) Selling and administrative costs15,000(7) Rent for building5,000(8) Depreciation15,000(9) Operating expenses$185,000

15、185,000(10) Net operating income$65,00042收益表（續(xù)）(10)Net operating income$65,000Less:(11) interest charges on equipment loan6,000(12) State and local taxes4,000(13)Net income before income taxes$55,000(14)Less: Corporation income taxes18,000(15)Net income (or profit) after taxes$37,000(16)Less: Divide

16、nds paid on common stock15,000(17)Addition or retained earnings$22,00043折舊$10,000$10,000$10,000$10,000$10,000$10,000$10,000$10,000$10,000$10,000The depreciation is taken in annual accounting charges over the assets accounting lifetimedepreciation = the capital goods historical cost or purchase price

17、.Depreciation = the annual cost of a capital input that a company actually owns itself.44資產(chǎn)負債表AssetsLiabilities and net worthLiabilitiesCurrent assets:Current liabilities: Cash$20,000 Accounts payable$20,000 Inventory80,000 Notes payable30,000Fixed assets:Long-term liabilities: Equipment150,000 Bond

18、s payable100,000 Buildings100,000 Net worthStockholders equity: Common stock200,000Total$350,000 Total$350,00045關于資產(chǎn)負債表 The income statement measures the flows into and out of the firm, while the balance sheet measures the stocks of assets and liabilities at the end of the accounting year. A balance

19、 sheet must always balance:Total assets = total liabilities + net worth46例子 Suppose total assets are down $40,000; liabilities remain unchanged. This means total net worth has decreased by $40,000, and should write net worth down from the previous $200,000 to only $160,000.AssetsLiabilities and net

20、worthLiabilities$40,000Net worthCommon stock $40,00047會計慣例 The most important assumption used in a balance sheet is that the value placed on almost every item reflects its historical cost . This differs from the economists concept of “value”.48財務欺詐 For example, the inventory of hot-dog buns is value

21、d at the price that was paid for them. A newly purchased fixed asset is valued at its purchase price (this being the historical-cost convention). 正是因為兩種可能的計價，為影響收益的會計欺詐提供機會。49說明 “收益表”是描述一指定會計時間段中貨幣流入和流出企業(yè)的情況。 “資產(chǎn)負債表”是指在某一特定的會計時刻，企業(yè)的資產(chǎn)、負債和所有者權益狀況。 總之，“收益表”是對一時段而言的，“資產(chǎn)負債表”是對一時點而言的。機會成本7.351機會成本 The op

22、portunity cost (機會成本) is the value of the good and service forgone (放棄). The opportunity cost includes all consequences (結果), whether they reflect explicit monetary transactions (貨幣交易) or not. 52The immediate dollar cost of going to a movie instead of reading your economics textbook is the price of

23、the movie ticket.The opportunity cost also includes the possibility of gaining a better understanding of microeconomics and therefore becoming more successful in business.53市場價格與機會成本 在一個良好運行的市場上，價格等于機會成本。$25.02 (Market price)$25.01 (Opportunity cost)$24.98生產(chǎn)、成本理論和企業(yè)決策附錄55生產(chǎn)函數(shù)的數(shù)值例子 The production fun

24、ction is a constant-returns-to-scale production function, a special case of the Cobb-Douglas production function.Q = output;L = labor; A = land.100 2QLA563464906006927758463164485486327057752824004905646326922453464234905486002002823464004484901412002452823163466543210123456Constant returns to scale

25、LaborLand573464906006927758463164485486327057752824004905646326922453464234905486002002823464004484901412002452823163466543210123456Diminishing marginal product of laborLaborLand82645448425834649060069277584631644854863270577528240049056463269224534642349054860020028234640044849014120024528231634665

26、43210123456Diminishing marginal product of landLaborLand52586777101593464906006927758463164485486327057752824004905646326922453464234905486002002823464004484901412002452823163466543210123456LaborLandABCDA、B、C和D點的產(chǎn)量相等。60給定產(chǎn)量的最低要素成本組合(1)(2)(3)(4)Input CombinationTotal cost Total costLaborLandPL=$2PL=$

27、2LAPA=$3PA=$1A1620?B23137C3212?D6115?881361等產(chǎn)量曲線3464906006927758463164485486327057752824004905646326922453464234905486002002823464004484901412002452823163466543210123456LaborLand62654321Land0123456LaborABCDqEqual-product curve or isoquantThere are an infinite number of equal-product contour lines (等

28、值線) in the map.63CAL替代率654321Land0123456LaborABDqMACLNMN: AMPA=L MPLALMPMPLA64等成本線654321Land012345678LaborLabor price = $2, Land price = $3TC=$3TC=$6TC=$9TC=$12TC=$15TC=$18equal-cost Line: TCqPqPAALL65替代率654321Land012345678LaborTC=$3TC=$6TC=$9TC=$12TC=$15equal-cost Line: TCqPqPAALLALAPA=L PLALPPLA66最低成本投入組合654321Land012345678LaborTC=$3TC=$6TC=$9TC=$12ABCDALMPMPLAALPPLAALALPPMPMP67最低成本條件ALALPPMPMPAALLPMPPMP68說明 等產(chǎn)量線方法一般用于企業(yè)的長期行為分析，因為對于長期來說，所有的生產(chǎn)要素都可以改變，所以可以在等產(chǎn)量線上進行選擇。 對于短期分析而言，按慣例一般不使用等產(chǎn)量線分析方法。69小結 經(jīng)濟成本，短期和長期的成本劃