微观经济学-微经课件productionand

5FIRM

BEHAVIOR

AND

THEANIZATION

OF

INDUSTRYContext:

PartIIntroductionPart

II

MarketPart

III

Consumer

Behavior

and

DemandSideIn

this

part:Technical

relationship

between

input

and

output

onsupply

side

of

marketInputs

------OutputsOutputs

varies

with

inputs----production

theoryInputs

and

their

costs

varies

withoutputs----costtheory13The

Costs

of

ProductionThe

Market

Forces

of

Supplyand

DemandSupply

and

demand

are

the

two

wordsthat

economists

use

most

often.Supply

and

demand

are

the

forces

thatmake

market

economies

work.Modern

microeconomics

is

about

supply,demand,

and

market

equilibrium.WHAT

ARE

COSTS?According

to

the

Law

of

Supply:Firms

arewilling

to

produce

and

sell

agreaterty

of

a

good

when

the

price

of

the

goodis

high.This

results

in

a

supply

curve

that

slopesupward.专业用语1．生产（Production）2．成本（Cost）3．利润（Profit）4.总产量（Total

Product,简称：TP）5.平均产量（Average

Product,简称：AP）6.边际产量（Marginal

Product,简称：MP）专业用语总成本（Total

Cost，TC）固定成本(Fixed

Cost，TFC)可变成本(Variable

Cost，TVC)平均总成本(Average

Total

Cost，ATC)平均固定成本(Average

Fixed

Cost，AFC)平均可变成本(Average

Variable

Cost，AVC)边际成本（

MarginalCost，MC)的类业主；合伙企业；公司；厂商的生产与成本为什么快餐食品那么快？为什么人多反而误事？为什么它们不增加里银幕那么多？为什么？如果你独自经营，那么，你必须挣

才刚好收支相抵？为什么即使你的分数与上学期相比有所提高，你的平均积分点也有可能下降？本章和下章介绍厂商的生产与成本，在这里你可以找到以上问题及其他问题的答案。前一章分析了需求曲线背后的消费者行为。本章供给曲线背后的生产者行为。

一章中，要求你像消费者或需求者一样思考的问题；在这一章中，你必须像生产者或供给者那样思考问题。你可能觉得自己作为一个消费者更真实（因为你确实是个消费者），但你没有

，你对生产者也有不少了解。你每天都处在生产者的包围之中，如书店、音像商店、百货公司、食品杂货店、便利店、衣物干洗店、

、饭店、工厂、，以及黄页薄和国际互联网上其他无数的生产者。虽然你自己可能还不是一个生产者，但你已经具有企业如何经营的概念。生产概述1、生产的概念生产：投入、产出的过程。生产：以营利为目的、付出脑力和体力的人类活动。2、生产要素说两要素说：劳动、土地；劳动、资本三要素说：劳动、土地、资本四要素说：劳动、土地、资本、企业家才能1.

Production

(13.2)Production

Function

and

Basic

ConceptsTheFunctionUsed

to

describe

relationship

between

inputs

andoutputsQ

=

f(

X1,

X2,

X3,

X4, ...

)um

output,

from

any set

of

inputsShort

runand

long

runQ=f(

X1,

X2,

X3,

X4, ...

)

,

ALL

factors

variableQ

=

f

(

X1,

X2,

X3,

X4, ...

)FIXED

IN

SR

VARIABLE

IN

SRChapter

13生产函数描述投入与产出之间的技术关系，表现为特定的要素投入与其获得的最大产出量之间的关系。著名的生产函数：C

D函数Q

f(L,K)Q

A

Lα

K

1

α其中：A-技术进步L-劳动

K-资本劳动的投入产出弹性生产要素投入劳动土地资本企业家才能产出物品劳务厂商生产函数在一定的生产技术水平下，生产要素投入量与最大产出量之间的物质数量关系Q=

f（L

,

K）生产函数概述PRODUCTION

AND

COSTSThe

Production

Function–

The

production

function

shows

thety

ofinputsusedty

ofoutput

ofrelationship

betweento

make

a

good

and

thethatgood.1.1.2

SomeParticular

Production

FunctionsA

function

is

homogeneous

of

degree-n,

ifmultiplying

all

inputs

by

λ,

increases

the

dependentvariable

by

λn.Q

=

f(

K,

L)So, f(

λK,

λL)=

λQA

Useful

Specific

function:

Cobb-DouglasProductionQ

=

A

•

Kα

•

L1-αCobb-Douglas

Production

Functions

arehomogeneous

of

degree

1

in

this

case.Q

=

f

(

K,

L)

for

two

input

case1.1.4

Time

Horizon

in

ProductionShortrun---- riod

that

at

least

one

inputcan

change

while

at

least

another

input

donot

have

enough

time

to

change.Long

run---- riod

long

enough

for

allinputs

to

change

as

producers

please.The

very

long

run----In

addition

to

inputs,technology

changes短期生产函数（劳动可变）短期生产函数：K不变，Ｌ可变，则与产量有关的几个概念总产量平均产量边际产量Q

=

F

(

L,K

)LAP =

F

(

L,K

)/

LTPL

=

F

(

L,K

)MPL

=

TPL/

LMPL

=

dTPL/

dLTP

、AP

与MP短期生产函数Q

=

f（L

,

K0）TPAPMP总产量企业在一定时期内生产的全部产量TP

=

Q

=

f（L）平均产量平均每单位变动投入生产的产量APL

=

TP/L边际产量每增加一单位变动投入所增加的产量MPL

=

dTP/dL三种产量的关系Marginal

Product–

The

marginal

productof

any

input

in

theproduction

process

isthe

increase

in

outputthat

arises

from

an

additional

unit

of

that

input.The

Production

FunctionDiminishing

Marginal

ProductDiminishing

marginal

product

is

the

propertywherebythe

marginal

product

of

an

inputdeclines

asthe ty

of

the

input

increases.Example:

As

more

and

more

workers

are

hired

atafirm,

each

additional

worker

contributes

lessandless

to

production

because

the

firm

has

a

limitedamount

ofequipment.Figure

2

Hungry

Helen’s

Production

FunctionCopyright

©

2004

South-Western(ty

ofOutputsper

hour)150140130120110100908070605040302010012345Number

of

Workers

HiredProduction

functionDiminishing

Marginal

ProductThe

slope

of

the

production

functionmeasures

the

marginal

product

of

an

input,such

as

a

worker.When

the

marginal

product

declines,

theproduction

function es

flatter.1.1.3

Basic

Product

ConceptsAverage

Product

=

Q

/

Loutput

per

labor,

which

is

variableMarginal

Product

=

△

Q/

△

L

=

dQ/dLoutput

attributable

to

last

unit

of

labor

appliedTotal

ProductL01202463702449222511018221.2

Short-Run

Production:

Law

of

DiminishingReturnLMarginal

ProductAverageProduct12

3

4

5LQM

PAP00------12020202345467092110262422182323.332322Think

about

average

grade

of

whole

theclass

and

grade

of

new

entrants.Delta

EpsilonGrade808010084Average

90Alpha

Beta

Gama90

80

7085

80LTotal

OutputMarginalProductLAverageProductInflectionpointHow

outputs

changes

with

changes

in

one

input?When

MP

>

AP,

then

AP

is

RISING–

If

your

marginal

grade

in

this

class

is

higher

thanyour

average

grade

point

average,

then

yourG.P.A.

Is

risingWhen

MP

<

AP,

then

AP

is

FALLINGIf

the

marginal

weightadded

to

a

team

is

less

thanthe

average

weight,

the age

team

weightdeclinesWhen

MP

=

AP,

then

AP

is

at

its

MAXIf

the

new

hire

is

just

as

efficient

as

the

averageemployee,

the age

productivity

doesn’tchange一种可变投入品生产函数假定两种投入中，资本固定，仅劳动可变，其生产函数如下表4567891其中，劳动平均产出（ALP）到4以后下降；劳动边际产出从第3个以后下降。注意生产函数是在给定知识和技术条件下成立的。理解为“在一定技术条件下特定的投入品组合有效使用带来的最大的可能性产出”。随着知识技术不断进步，生产函数会发生变化。一种可变投入品生产函数：几何图形表达总产出曲线上某劳动投入数量点的劳动平均产出是该点与原点连线射线的斜率。B点与原点斜率为60/3=20。某劳动投入量的边际产出是总产出曲线上过该点切线的斜率。B点前后先升后降。D点的切线斜率为零，总产出最大。当边际产出高于平均产出时，平均产出上升；反之下降；边际产出在平均产出的最高点处从上到下穿01234

567

8901210ABC60112102030每月产量每月产量E总产量平均产量边际产

量3

4

5

6

7

8

9D10

每月投入劳动每月投入劳动短期产量曲线（劳动可变）APTPMPQLTPLOAPMPLOL1

L2

L3L1

L2

L3MPTPAPT

P

与

M

P斜

率

边

际拐

点

顶

点顶

点

零

点T

P

与

A

P射

线

平

均M

P

与

A

PMP>AP

AP递增MP=AP

AP最大MP<AP

AP递减Law

of

Diminishing

ReturnsINCREASES

IN

ONE

FACTOR

OF

PRODUCTION,HOLDING

ONE

OR

OTHER

FACTORS

FIXED,AFTER

SOME

POINT,MARGINAL

PRODUCT

DIMINISHES.A

SHORTRUN

LAWpointofdiminishingreturnsVariable

inputMPButalsoholdfor

longrun

when

factorproportion

changes边际

递减规律含义：当两种要素结合生产一种产品时，若技术水平和其他要素投入固定不变，只有一种要素投入变动，随着该可变要素投入的增加，其边际产量减少原因：不变投入和可变投入的组合比例变化，比如技术一定，生产要间有一个最佳的配比。理解注意几点：收益递减规律具有独立于经济制度或其它社会条件而发生作用的普遍性或一般性。边际收益递减规律作用前提之一“技术水平”不变，它不否认技术条件变化可能导致劳动生产率提高。规律表述有“最终”二字修饰条件。也就是说，某一投入边际收益并非自始至终递减，它有可能在一定范围内呈现增加趋势。边际递减举例：和尚吃水第一个阶段，平均产出递增，因为生产的规模效益正在表现出来；（一个和尚挑水吃）第二个阶段，平均产出递减，总产出增长的速度放慢；（二个和尚抬水吃）第三个阶段，边际产出为负，总产出绝对下降。（三个和尚没水吃，减员增效）生产合理区域在第二个阶段。0EⅠFQTPⅡ

ⅢAPLMPQL0ABⅠⅡⅢTPFMP>APAPMP<APAPMP<0TPMP=APAP最大EAPMP=0TP最大生产阶段的划分APMPLOL2

L3APMPI

II

III平均产量递减边际产量为正平均产量递增边际产量为负理性厂商选择第II阶段两种可变投入情况与等产量线：长期假定“劳动和资本两种投入都可以变化”代表了经济分析的长期情况，而“长期”和“短期”是经济学分析方法中两个极为重要的概念，与日常语义具有不同含义。

用短期和长期来表示微观经济主体调节行为受限制程度不同的两类时间条件：短期表示受到限制较小，因而调节时间较短，如厂商对于劳动，原料投入数量的调节等属于短期问题；长期则指调节受到的限制较大，因而需要调节时间较长，如通过固定资本投资来改变企业最大产出能力。不 业不同企业的“长期”对应的具体时间长度有显著差别。长期生产函数Q

=

F

(

L,

K

)L，K均可变，并可互相替代问题：企业如何确定L，K的组合比例？等产量线等成本线最优要素组合长期生产函数：表

方式投入要素都发生变化的情况下，所谓长期生产函数的表

表示：劳动投入资本投入12345120405565852406075859035575901001054658510011011557590105115120表中数据表示不同劳动与资本投入量组合能够提供的最大产出量（即技术上最有效率的产出量）。从横向看，在资本投入量固定时产出随着劳动投入增加而增加；从纵向看，在劳动投入量固定时产出随着资本动投入增加而增加。长期生产函数：模型方式每年投入资本表 数据的几何表达：等产量曲线（注意：直接描图得到的是不平滑图形，平滑处理是假定了投入品无限细分的可能性）。等产量线Q1表示获得55个产出的投入品组合的集合：A点表示1单位劳动与3单位资本组合可以得到

55单位产出，D点则表示3单位劳动与1单位资本组合同样可以得到55单位产出。Q2与Q3则分别表示获得75个和90个产出的投入品组合的集合。

Q2位于Q1的右上方，表示如果要生产

的产量，必须投入

的劳动或（和）资本。等产量线的集合又称作等产量图，它描述了企业的

1生产函数，即通过采用一定技术和不同投入品组合来获得不同数量的产出。每年投入劳动0123452345Q2=75Q1=55Q3=90ABCDE等产量曲线概念1、等产量线（1）概念:生产某一特定产量的不同生产要素组合点的集合。Q

f

(L,K)L、K均是可变要素等产量线上不同的生产要素组合所生产的产量没有区别。等

产

量

曲

线技术水平不变的条件下，生产同一产量水平所使用的两种要素各种组合的轨迹KLOQ3Q2Q1等产量线特征斜率一段为负，两段为正。等产量线有无数条，越远离原点产量越高。任何两条等产量线不相交。凸向原点。LOQ1K1K2L1

L2⊿K⊿LMRTSLK⊿L=

-

⊿K

dKdLMRTSLK

=

-LKMRTS

=MPLMPK边际技术替代率在技术和产量不变的条件下，增加一单位某种要素的投入所能减少的另一种要素的投入量劳动替代资本的边际技术替代率K边际技术替代率的变化趋势边际技术替代率：经济含义和数学表达等产量线的斜率表示在保持产出不变前提下一种投入品与另一种投入品的替代关系，即：MRTS

=

- K

/ L

。如果用数学推导，可以发现MRTS是两种投入品边际产量的比率：如果生产函数是Q=f(x1,x2)则MRTS=-d

x2

/d

x1

(条件是Q保持不变）。依据全微分公式：dQ=Q/x1(dx1)+Q/x2(dx2)由于产量不变即dQ=0，∴

Q/

x1(

dx1)

+

Q/x2(

dx2)

=

0

；dx2

/dx1

=

-

Q/x1

/(

Q/x2)∵

Q/x1

和

Q/x2

分别是两种要素的边际产品∴dx2/dx1

=

-

MP1

/

MP2；即MRTS是两种投入品边际产量的比率。边际技术替代率递减性质等产量线凸向原点，几何含义表示曲线从左到右的斜率绝对值越变越小。即边际技术替代率越变越小.右图表示，产出为75等产量线的

MRTS从2减少到1，到2/3，再到

1/3。MRTS递减性质的经济含义是，当大量使用劳动来替代资本时，劳动的生产率会下降；同样，大量使用资本来替代劳动时，资本的生产率会下降；因而，生产过程应“平衡”和“适当”地利用劳动和资本。每月投入资本每月投入劳动012345123451Q

=75Q2=90K=1/3L=1L=1L=1K=2K=1L=1K=2/3等成本线图形：要素价 既定的条件下，花费一定成本所能够 的两种要素最大数量组合的轨迹OLC0rC0w问题：等成本线的斜率等成本线位置的决定等成本线位置的变动概念：在生产经费及生产要素价

即定的情况下，生产者所能到的最大的各种要素的组合。K数学公式：C0

=wL+rK等成本线的变动LKKL总成本增加或减少工资增加或减少生产要素的最优组合最小成本最大产量成本既定产量最大

产量既定成本最小KOLAQ3Q2Q1BCD-dK/

dL

>

w

/rMPL/MPK

=

w/r生产者均衡（1）概念：生产者均衡点是指生产者在现有生产经费、生产要素价及技术水平的约束下，追求到最大的产量。（2）生产者均衡点的位置：等产量线与等成本线的相切点。生产者均衡点K0LK*L*E0M/PKM/PL等成本线等产量线生产者均衡的理解产量最大化条件PL.K+PK.K=MMPK

MPLPK

PLK②0LE0K*L*●M/PLM/PK等成本线的斜率为：推导式②：等产量线的斜率为：MRTS

K

MPLL

MPKPK

PL∵在均衡点有PKMPKMP

P

L

L∴PK

PLMPK

MPL已知：生产者均衡点的变动（1）0LE0●1、生产经费增加等成本线水平右移M→M′=M+△MKM/

PKM′/

PLM′/PKM/PLE1●PL.L+PK.K=M′生产扩展线生产者均衡点的变动（2）0E1E0●LM/

PL

′M/PL2、要素的价

变动，等成本线旋转。∵PL→PL′∴等成本线斜率变化=-PL′/PKKPL′.L+PK.K=MM/PK生

产

扩

展

线KLQ1Q3Q2S1S2等斜线等产量曲线上边际技术替代率相等的点的轨迹OKLOQ2Q1Q3LTC扩展线由成本变动引起的最优要素组合变动的轨迹脊线与生产经济区域KLOQ3KMP

<0AQ2Q1

MPL<0脊线B脊线生产的经济区域脊线等产量线上斜率为0的点或者斜率为∞的点与原点的连线生产的经济区域两条脊线所围的区域脊线的理解(1)KLABC·D·50100150C点是等产量曲线上斜率为正的弧段上的一点,却在脊线之外，与D点比较，C点需要

的资本、

的劳动，由于资本和劳动的价

不可能为负，这样企业在D点经营一定比在C点经营更便宜。脊线的理解（2）脊线的概念：由等产量线上斜率为零及斜率无穷大的点所构成的区域脊线所含区域等产量线斜率为负，是生产合理投入的区域（经济区域）。在合理投入区AOB内：MPL>0；MPK>0即：K,L;L,K称为有效替代。LL1K1OKA●●●●●●●●●●B●规模与长期生产函数600500400300200100700规模所有要素投入同时、同方向、同幅度变动时引起的产量变动KLO规模 递增：

产量的增加幅度大于要素的增加幅度规模 不变：

产量的增加幅度等于要素的增加幅度规模 递减：

产量的增加幅度小于要素的增加幅度长期生产函数Long

Run

Production:

Returns

to

ScaleScale

Changes

and

Returns

to

ScaleWe

call

it

scale

changes

that

all

inputs

changeinabout

the

same

proportionReturns

to

scale

refer

to

changes

in

output

resultingfrom

changes

in

all

inputsThree

Kinds

of

Returns

to

ScaleConstant

Returns

To

Scale

(CRS)doubling

of

all

inputs

doubles

outputIncreasing

Returns

To

Scale

(IRS)doubling

of

all

inputs

MORE

than

doubles

outputDecreasing

Returns

To

Scale

(DRS)doubling

of

all

inputs

DOESN’T

QUITE

doubleoutput1.3.3

Cobb-Douglas

Production

Function

andReturns

to

ScaleQ

=

A

•

Kα•Lβ

is

aCobb-DouglasProduction

FunctionIMPLIES:Can

be

IRS,

DRS

orCRS:if

α+β=1,

thenCRSif

α+β

<

1,

then

DRSif

α+β

>

1,

then

IRS1.3.4

ReasonforReturns

to

ScaleIncreasing

Return

to

Scale:Product-specific

economiesspecializationPlant-specific

economiesIndivisibility of

Lumpy

EquipmentEconomies

in

overheadEconomies

in

required

reserves

and

investment(maintenance)economies

of

scope

(interactions

among

products).Firm-specific

economieseconomies

indistribution

and

transportation

of

ageographically

dispersed

firm,

or

economies

in

marketing,sales

promotion,

or

R&D

of

multi-product

firms.Decreasing

Return

to

ScaleProblems

of

coordination

and

control

as

it

ishard

to

send

and

receive

information

as

the

scalerises.Other

disadvantages

of

large

size:slow

decision

ladderInflexibility1.3.5

Trend

of

Return

to

ScaleIRS ,

and

thenCRS,

andDRS

finally1.4

The

Very

Long

Run:

Technological

ChangesTechnological

changes

alter

production

functionsGiven

inputs

can

produce

more

outputs2002

South-WesternPublishing2.

CostThe

meaning

and

measurement

of

costShort-run

Cost

FunctionsLong-run

Cost

FunctionsLinks

between

Cost

and

ProductionScale

Economies

and

CostWHAT

ARE

COSTS?According

to

the

Law

of

Supply:Firms

arewilling

to

produce

and

sell

agreaterty

of

a

good

when

the

price

of

the

goodis

high.This

results

in

a

supply

curve

that

slopesupward.WHAT

ARE

COSTS?The

Firm’s

Objective–

The

economic

goal

of

the

firm

is

toprofits.izeTotal

RevenueThe

amount

a

firm

receivesfor

the

sale

of

itsoutput.Total

CostThemarket

value

of

the

inputs

afirm

usesinproduction.Profit

is

the

firm’s

total

revenue

minus

itstotal

cost.Profit

=

Total

revenue

-

Total

costA

firm’s

cost

of

production

includes

all

theopportunity

costs

of

making

its

output

ofgoods

and

services.Explicit

and

Implicit

CostsA

firm’s

cost

of

production

includeexplicitcosts

and

implicit

costs.Explicit

costs

are

input

costs

that

require

a

directoutlay

of

money

by

thefirm.Implicit

costs

are

input

costs

that

do

not

require

anoutlay

of

money

by

thefirm.商为提供一定量的某种产品或服务所实际花费的生产要素的价值成本厂商或租用要素的花费显性成本隐性成本厂商自身拥有的并投入到生产中的要素价值成本机会成本的含义机会成本是经济学中最具有闪光点的思想之一，它与资源的稀缺和资源的多种用途相联系。为了获得某种产品，必须放弃什么?当一种资源投入某一用途以后，就失去了作为

的可能性。其它诸用途中的最大收益就是资源投入该用途的机会成本。机会成本是从社会角度来看有限资源用于某一经济活动的代价。但放弃的用途难于穷尽，获利也有很大的不确定，所以机会成本的计算是的。它对于经济决策是至关重要的。读大学、读

的机会成本是多少呢?Economists

measure

a

firm’s

economicprofit

as

total

revenue

minus

total

cost,including

both

explicit

and

implicit

costs.Accountants

measure

the

accounting

profitas

the

firm’s

total

revenue

minus

only

thefirm’s

explicit

costs.When

total

revenue

exceeds

both

explicitand

implicit

costs,

the

firm

earns

economicprofit.–

Economic

profit

is

smaller

than

accountingprofit.Figure

1

Economic

versus

AccountantsCopyright

©

2004

South-WesternRevenueTotalopportunitycostsHow

an

EconomistViews

a

FirmHow

an

AccountantViews

a

FirmRevenueEconomicprofitImplicitcostsExplicitcostsExplicitcostsAccountingprofitTable

1

A

Production

Function

and

Total

Cost:Hungry

Helen’s

FactoryCopyright©2004

South-Western2.1

Meaning

of

Cost in

Economics

(13.1)There

Are

Many

Economic

Cost

Concepts2.1.1

Various

Cost

Conception

Relevant

to

Economic

CostOpportunity

Cost

--

value

of

next

best

alternative

use.Explicit

vs.

Implicit

Cost

--actual

prices

paid

vs.opportunity

cost

ofowner d

resources.

(Value

of

one’sown

resources)Accounting

Cost

—Actual

paymentSunk

Costs

--

already

paidfor, or

there

is

already

acontractual

obligationto pay

but

cannot

be

recovered.It

isirrelevant

in

decision

making.Cost

ItemActualExpenditureValue

NowMeat

and

vegetables500500Kitchen

appliances1000500Waitress

hour10001000Decoration20000Utilities500500In

sum50002500Own

effort2000Service

of

familymember1000Ownhouse500TOTAL500060002.1.2

Understand

Cost

as

an

EconomistWhendo

you

start ng

the

business?,

we

do

not

consider

opportunity

costs

(

the

explicit

costs

are5000

instead

of

2500)Revenue:

4000？8000？9000？

or

more?Second,

we

do

not

consider

the

difference

between

explicit

costsand

implicit

costs

(Suppose

no

implicit

costs)

:Revenue:

2000？3000？5500？or

more?Third,

when

will

you

run

the

business

if

all

cost

consideredRevenue:

3000？5500？6500？8000？9000？CostsActual

PaymentsOpportunityCosts(Accounting

Costs)Explicit

Cost50002500Implicit

CostNA3500In

Total500060002.1.3

How

economists

measure

a

variety

of

Costs?Depreciation

Cost

Measurement.

Accounting

depreciation(e.g.,

straight-line

depreciation)

tendsto

have

littlerelationship

with

the

actual

loss

of

valueTo

an

economist,

the

actual

loss

of

value

isthe

true

cost

ofusing

machinery.Inventory

Valuation.

Accounting

valuation

depends

on

itsacquisition

costEconomists

view

the

cost

of

inventory

asthe

cost

ofreplacement.–Unutilized

Facilities.

Empty

space

may

appear

to

have"nocost”Economists

view

itsalternative

use

(e.g.,

rentalvalue)

asits

opportunity

cost.2.1.4

Measures

of

Profitability

andDecisionAccountants

and

economists

view

profitdifferently.Accounting

profit,

at

its

simplest,

is

revenuesminus

explicit

costs.Economists

include

other

implicit

costs

(suchas

a

normal

profit

on

investedcapital).Economic

Profit

=

Total

Revenues

-

ExplicitCosts

-

Implicit

CostsAll

Costs

are

understood

as

opportunity

costShoreham

Power

Plant

in

LongIslandCostRevenuecategoriesvalueSituation

1Situation

2Initialexpenditure1.5

billionSunk

cost1

billionIncrementalcost

if

run

it0.6billion0.7billion1.2billion1972Plan

as

ofExpectation

of

futureMarket

Share

of

Titanium

Dixiode34%33%33%Dupont National

Lead Another

SevenMarket

Share

of

Titanium

Dixiode18%18%64%Dupont National

Lead Another

SevenNew

regulation;Rising

price

of

materials;Growing

demandPotential

RivalStay

outsideEnterDupont’sStrategyMaintainhigh

priceDupont：100Rival：0Dupont

：60Rival

：40Price

cutDupont

：50Rival：0Dupont：50Rival

：-5Dupont’s

Threat

as

a

StrategyPotential

RivalStay

outsideEnterDupont’sStrategyMaintainhigh

priceDupont：100Rival：0Dupont

：10Rival

：40PricecutDupont

：50Rival

：0Dupont：20Rival

：-5Examples

of

Sunk

CostConduct

a

desperate

fight

(throw

away

the

scabbard

)Mao’s

CourageBlind

knightOuting

Decision

with

yourown

car

vs.

with

rented

carAirfare

discountCourage

of

a

man

suffering incurable

diseaseFootball

ticket

or

movieWhat

is

the

true

cost

of

attending

this

course?Sellrefrigerator和会计师的区别利润概念有差别根据利润是正还是负决定是否营业会计师要比较不同项目的利润和会计师决策的结果是一样的，只是用到的工具不同和会计师在租房决策上的区别：已经租房签约一年，月租500元；到第五月时，租房者欲长期离开

，决定转租，此时市场

上升至700元。一位同学愿意花600元租房。会计师：(1)出租给该同学，(会计)利润为100元；(2)出租给他人，(会计)利润为200元。不租给该同学。：(1)出租的机会成本为700元；(2)出租给该同学的收益为

600元。经济利润为－100，不租给该同学。return2.1.5

SummaryEconomic

cost

=

explicitcost

+

implicit

costBoth

explicit

and

implicit

cost

are

measured

byopportunity

costSunk

cost

is

excluded

from

economiccostIn

economic

cost

is

included

normal

profitNormal

profit

isunderstood

opportunity

cost

of

runningthe

business

project

or

investment

programThe

lowest

cost

of

different

possibilities

(a

technicalconcept)2.2.

Short

Run

Costs

(13.3)2.2.1

Various

Short

Run

CostsTC

=

FC

+

VC fixed

&

variable

costsATC

=

AFC

+

AVC

=

FC/Q

+

VC/QMC

=△C/

△

QcalculationcompositionTotalAverageMarginalFixedFCAFCNot

availableVariableVCAVCMCAdditionTCATCMC短期成本函数1.总成本：产某一既定产量的总成本等于生产过程中所使用的每一种投入要素成本之和。TC=TFC+TVC

总固定成本+总变动成本2.固定成本：短期生产过程中所有固定不变的投入要素的成本，是不随产量变化的常数。短期平均成本和边际成本1.平均总成本：ATC=TC/Q2.平均固定成本：AFC=FC/Q3.平均变动成本：AVC=VC/Q4.边际成本：MC=TC/Q=VC/Q对于

续的TC函数：MC

=

d(TC)/dQ

=

d(VC)/dQ2.2.2

Short

Run

Cost

GraphsAFCQ1.Q2.AVCMC

intersects

lowest

pointof

AVC

and

lowest

point

ofATC.When

MC

<

AVC,

AVCdeclinesWhen

MC

>

AVC,

AVC

risesJust

think

about

your

grade

in

school3.QAFCATCAVCMC2.2.3

Relation

of

Cost

&

Production

Functions

inSRThe

reason

for

costs

changes:Law

of

diminishing

marginal

returnAP

&

AVC

are

inversely

related.(ex: oneinput)AVC

=

WL

/Q

=

W/

(Q/L)

=

W/

APL–

As

APL

rises,

AVC

fallsMP

and

MC

are

inversely

relatedMC

=△

TC/

△

Q=W△

L/△Q=W/(△Q/△L)

=

W

/

MPL–

As

MPL

declines,

MC

risesproduction

functionsMPLAPcost

functionsMCAVCThe

relationship

between

the ty

afirm

can

produce

and

its

costs

determinespricing

decisions.The

total-cost

curve

shows

thisrelationship

graphically.Table

1

A

Production

Function

and

Total

Cost:Hungry

Helen’s

FactoryCopyright©2004

South-WesternFigure

3

Hungry

Helen’sTotal-Cost

CurveTotalCost$8070605040302010ty(of

Outputs

per

hour)Copyright

©

2004

South-Western0

10 20

30

40

50 60

70Total-costcurveTHE

VARIOUS

MEASURES

OFCOSTCosts

of

production

may

be

divided

intofixed

costs

and

variable

costs.Fixed

costs

are

those

costs

that

do

not

vary

with

the ty

of

output

produced.Variable

costs

are

those

costs

that

do

vary

with

the ty

of

output

produced.Total

CostsTotal

Fixed

Costs

(TFC)Total

Variable

Costs

(TVC)Total

Costs

(TC)TC

=

TFC

+

TVC短期成本曲线Average

CostsAverage

costs

can

be

determined

by

dividingthe

firm’s

costs

by

the ty

ofoutput

itproduces.The

average

cost

is

the

cost

of

each

typicalunit

ofproduct.Average

CostsAverage

Fixed

Costs

(AFC)Average

Variable

Costs

(AVC)Average

Total

Costs

(ATC)ATC

=

AFC

+

AVCAFC

Fixed

cost

FCty

QAVC

Variable

cost

VCty

QATC

Total

cost

TCty

QMarginal

CostMarginal

cost

(MC)

measures

the

increaseintotal

cost

thatarises

from

an

extra

unitofproduction.Marginal

cost

helps

answerthefollowingquestion:How

much

does

itcost

to

produce

an

additionalunit

of

output?MC

(change

in

total

cost)

TC(change

in

ty)

QMarginal

Cost

Thirsty

Thelma’s

LemonadeStandtyTotalCostMarginalCosttyTotalCostMarginalCost0$3.00—13.30$0.306$7.80$1.3023.800.5079.301.5034.500.70811.001.7045.400.90912.901.9056.501.101015.002.10Total

Cost$15.0014.0013.0012.0011.0010.009.008.007.006.005.004.003.002.001.00tyof

Output(glasses

of

lemonade

per

hour)0Total-cost

curveCosts$3.503.253.002.752.502.252.001.751.501.251.000.750.500.25tyofOutput(glasses

of

lemonade

per

hour)0MCATCAVCAFCMarginal

cost

rises

with

the

amount

ofoutput

produced.–

This

reflects

the

property

of

diminishingmarginal

product.Costs$3.503.253.002.752.502.252.001.751.501.251.000.750.500.25tyofOutput(glasses

of

lemonade

per

hour)0MCThe

average

total-cost

curve

is

U-sh

d.At

very

low

levels

of

output

average

totalcost

is

high

because

fixed

cost

is

spreadover

only

a

few

units.Average

total

cost

declines

as

outputincreases.Average

total

cost

starts

rising

becauseaverage

variable

cost

rises

substantially.The

bottom

of

the

U-sh d

ATC

curveoccurs

at

the

ty

that

minimizesaverage

t