Macroeconomics

: E-mail: wqiuju@126.comTel: 13313651517

Land LaborMental Talents LaborPhysical Labor Entrepreneurship

whatHow?For whom

Opportunity CostKABC500600700A

1.1AF

11.811108

5

BCDEFA 1 2 3 4 51.1

1.2

Allocation of Resources

Microeconomics Macroeconomics

2 1

what ought to bethe way things are

Equilibrium Analysis Unequilibrium Analysis

(1) A B C D (2) A B C D B D

3 A.B.C.D.A

Perfect Competition MarketMonopoly MarketMonopolistic Competition MarketOligopoly Market

Demand willing needswantsdesires able

Demand FunctionQd=fabc

PQd

Qd=abP abab

The Law of DemandPQPQ0

P

Q Dab

1.0

P

QDabP0Q0P1Q1

2.

PQD

ABA A.A B.A C.B D.BD

1 --- --- Supply

2

Supply Function QS=fbc QS=abP

PQ PQ 0

P

QSab

OOPQPQ PQO

1.

2.

:

A B C D D A

Price controls 1.Price floor

PQDSP0OQ0P1Q1Q2 excess supplyE

2.Price ceiling PQDSP0OQ0P1Q1Q2excess demandE

1.

2. A Supply ShiftS1

S2S3Q3P2P1PDQ1Q2Q

P3E1

E2E3O

DS QP1DD1P SPQD2DD2 P3DD3 P3. S S1P

()

1EQ3P1P3P2

PPEPtOQQEQ2OSDQ1

2.EP1SDQEPEQO

PQ4P3Q3P2Q2Q1tOP

3SDEQePeQOPP1Q3P2Q2Q1tOP

O

PQDPDQOO

elasticity

1. Ed

2.

ab544008005445

abba QPPQ

3 PQ

4. E = 0 perfect inelastic

E = perfect elasticPQD2O

E = 1 unitary elastic = D3OPQ

E < 1 inelastic

E > 1 elastic D56%9%POQ

5.dQ/dP

CCO

PQF

CGQd=f(P)A

BdPdQ

Q=f(P)OPQDCBEAed=ed>1ed=1ed

ABCDB

3.1.2.4.

5.

TR = P * Q 3101.(Total revenue

2. E > 1Ed=2P1=500/Q1=100 10% 10%20% P2=500 500*10%=450/ Q2=100+100*20%=120 TR2=P2Q2=450120=54000 TR1=50000 TR2 TR1=54000 50000=4000 TR2 >TR1

10%20%P3=500 +50010%=550/Q3=100 -10020%=80 10%TR3

E > 1,,; ,,1QOP

ABC

3. E < 1Ed=0.5P1=0.2/Q1=100 10%10%5%P2= 0.2 0.210%=0.18/Q2=100+1005%=105TR1=P1Q1=0.2100=20TR2=P2Q2=0.18105=18.9TR2 TR1=18.920= -1.1TR2

10%10%5%P3=0.2 +0.2*10%=0.22/Q3=100 -100*5%=95 TR3=P3Q3=0.2295=20.9TR3 TR1=20.9 20= 0.9TR3>TR1Ed=0.5P1=0.2/Q1=100

E < 1,,;,,

1.10%5%0.5

2. 5A. Em1superior goods Em0 B. Em1 C. 0 Em1essential necessary goodsnormal goods

D. Em =0 E. inferior goodsGiffen goodsEm0

3./

Sheet1

%

52

30

35

16

16

11

13

Sheet2

Sheet3

Sheet1

%

30

30~40

40~50

50~60

60

Sheet2

Sheet3

1. 1

2.

3.Ec0 YP XQXY Ec0 YP XQ XY Ec =0

1. A

P

QO

2.

3.>1

Es=1Q ES=P ES=04. OQOSP

Q ES1PEs1QOS(a)QOS(b)PP

5.

O

1.U12 = Utility

123 2.cardinal utility

1012345201018242830

TUMUTU Total UtilityMU Marginal Utility MU TU 0 0 0 1 30 30 2 20 50 3 10 60 4 0 60 5 -10 50

Law of Diminishing Marginal Utility

TUMUMU > 0, TU ;MU < 0, TU ; MU = 0, TU TUQTUMUQMUPPOO

1.

1212P88 3\4

QQ0ABP0OPP=f(Q)P0Q0

ordinal utility

indifference curves1 X2X1UX1X2O

X2X1U0ADX1X2 X2X1X1X212U0 O

X1

X2

a

1

4

b

2

3

c

3

2

d

4

1

24.3.2.5.

U1U2U3X1X2U4O

MRS Marginal Rate of Substitution of Commodities 1.

X-1

2

3 X1X2X1dX1X2dX2dU=0

4MRSMRS121:1

U1U2 0 1 2 3 4210

budget line1X20ABX1AX1X2BX2X1X1X2

2IX1X2P1P2 BAOX2X1P1X1+P2X2=I

31IP 2 IP X2X1O

3IPX2X1X1X1X2X2X1X1X2X2OO

E12 X1X2OAB

UABCD,U2EU3U1MNBACDOMNABU2U1U2X1X2

1

2 Px2Py1I20

-E1E2E3OAX2X1U3U1U212B3

E1 E2 E3P1X1-X1

IC2X3X2X1

OPCYXOAD4.16

P(b)(a)P1P2P3X3X2E2E3E1B3B1B2IC3IC1X

M1ABA1B1

M2ABA2B2A1B1YXBAEM0

1 O

n i=12n

product function2030

short runlong run

21

TPAPMPTPtotal product APaverage product AP = TP/QMPmarginal product

QLTPAPEL2GMPOL3L1FAB

1TPAP MP>APAPMP

law of diminishing marginal productivitylaw of diminishing marginal productivity

QLTPAPEL2GMPOL3L1FAB

A.B.C.A. B.C.0 D. E.

3MPAPLK

QLTPAPEL2GMPOL3L1FAB

MP>APAPMP

12

1.

Q LK12345120405565752406075859035575901001054658510011011557590105115120

2.A.

B.

C.

Q1Q2Q3LKQ4

D.Q1Q2ACB

3. 1;0 ABCK1L

2KOLq3q1q2ABCACB

AB

KLQ2EQ3Q1MNBACDE O

Q=fLK=LK-0.5L2-0.32K2QKLK=10123APLAPL=MPL=2

Expansion path

1. accounting cost opportunity cost

2. explicit cost implicit cost +

3normal profiteconomic profitexcess profit

4

C=F[Q]=F[ fLK]

0QLQCbSTCTVCTFC0TP

C=3Q3+2Q2+5681STC2Fixed cost 3 (Variable cost) STC = SVC + SFC TC = VC + FC = (Q) + b (Q) VCbFC

QCbSTCTVCTFC0

SAC SMC1SAC AC = TC/Q=VC/Q+FC/Q=AVC + AFC 2SMC SMC = dTC/dQ = d(VC+FC)/dQ = dVC/dQ = '(Q)

TC=Q3-12Q2+60Q+40AC=MC=

3. MCTC TVCCC0 0FCQQTCVC40MC ACAVCAFC 1 4 6 7 1 4 6 7 aabcbbcdd

4ACMCAVCMC 1) MCAC,QAC 2) MC = AC , ACmin 3) MCAC , QAC

MCACAVCQC0minBAPQB QATR

LTCLACLMC

1LTC)2(LAC)3(LMC)

LTCLTC

B2B1B30QE1E2E3Q1=50A2Q2=100Q3=150A1A3OKRLCLTCwOB3+rOA3wOB1+rOA110050ba150wOB2+rOA2

E150A1B1wE1wOB1+rOA1

E1bLACE1LTCE1E2E3

LTC Q3 Q1 Q2PRSLTCSTCLTCSTCLTCSTC

Q1Q2Q3LACPSRLACSACLACLACSACLACLACSACLACLACSACLACSAC

TCQOACMCQOLMC

SMC3SMC2SMC1LMCminE1E2E3COQ1QQ2Q3SAC1SAC2SAC3LAC LMCSMCLACLMCSMCLACSAC

1200400A B C 200D A

2LAC=SACLAC>LMCALACBLACCSACDSMC=SACB

3200100A B 0.5C C

12 SACsSACmSACL minminLACC0Q

Perfect Competition1234

1DPQ

2

1TRARMR TR(Q)=PQ AR(Q)=TR(Q)/Q=P MR(Q)= dTR(Q) / dQ=P2TR3ARMRdMRARP

QOPQOPdMRARPTR

PabQ TR=PQaPbQ2AR=PabQMRa2bQ

MR=MCTRTC

P,QOMRMCQOMR=AR=PQ1Q*

MCP0S0D0P00Q 0PP ,C, RAR=MRACacPcQ0Q 0P,C,RMCACAR=MRP0acPcQ 0QQ0Q0 : P>AC, > 0 P =AC, = 0 P

PQd1d2d3d4d5SACSMCAVCOE1E2E3E4E5p1p2p3p4p5q5q4q3q1q2

1E1ARSAC2E2ARSAC3E3AVCARSAC4E4ARAVC5E5ARAVC

STC=0.1Q32Q2+15Q +10P=551 2

PQSMCAVC0E1E2p1p2p5q2q1Qs = f ( p )SMC

MR = LMC = SMC = LAC = SACMRARP

PQOSACLACSMCLMCPQODMR=LMC=LAC=SMC=SAC

(constant-cost industry )LSd1P1D2P1E1QT1E2QT2P2d2P2AFQ2S2QT2E2

(increasing-cost industry )

(decreasing-cost industry )

S(LMC)S(LMC)S(LMC)P0QP0Q 0PQ

Complete Monopoly

1 2 3 4

12

1TRARMR1ARP2AR=2MR

MRARMR>0TRMR1MR>0Ed

TC=10+5QMC=dTC/dQ=52.04MR=MC MC=5=P1-1/2.0=MRP=5/0.5=10 E=4.0 P=5/0.75)=6.67/

Q=50-2PA 15B C P=25D A

TCTR

1P>AC

2P=AC

3AVC

STC=0.3Q3 +6Q2+140Q=1402P

SMC = MR

MR=MC

MR=LMC=SMC

MR=LMC=SMCGLMCLACBQ2ASAC2SMC1SAC1FSMC2E2Q1MRPQOdARE1

1TR100QQ2TC106QMRMCQ47 PARP532MC602QQ100PMRMCMR1002QQ10

Price Discrimination

MC=MRP=MC

= HPmF= HEF

HIDeadweight LossJ= PmIEF= HIE

HIJP=MC= HIG= 0I

Q1P1Q1QmPmQmQcPcP=MC

PQOn

MCHIGEJKL

MRa=MRbMC

EaEbPaPbEaEbPaPbEaEbPaPb PaABPbQbQaMRaMRbDaDbEaEbOMRa=MRbMCMRP11/Ed Pa11/Ea= Pb11/Eb

1 23

CBAQ0 Q1 Q2 Q3 DEdQd1d2P0P1P

1.

abMCAR0AR1MR0MR1DQP,R,C0TCP,R,C0P0PCMCACAR(d)MRQQ0acbDP0Q0

2.SMC=MR > 0 , AR > AC = 0 , AR = AC < O , AR < ACP,R,CP,R,CP,R,C(1)(2)(3)MCACAR(d)MR0Q0P0PCacbDQ 0MRQ 0MCACAR(d)MRMCACAR(d)QDD- Q0Q0P0PC

:A.B.C.D.C

MR=LMC=SMC AR=LAC=SAC D=d

ESACHMRPQdARPeDLMCOSMCLACAR = SAC = LACMR = SMC = LMCD = dQePQ

: A.MR=MC B.MR=LMC=SMC=LAC=SAC C.MR=LMC=SMCAR=LAC=SAC D.MR=LMC=AMC

oligopoly1234

1

1

2P=60QQQ=Q1+Q2MC1=MC2=01R1R1=PQ1=60QQ1 =60Q1Q12 Q2Q1MR1=302Q1Q2MR1=MC1602Q1Q2=0 2Q2=30Q1/2

1933DAOQ3BQ3Q1OQ1OP1ABOQ1EPl

SMCMR

cDMRMRMCEQPMC1MC2E1E2Q1Q2 EMC2MC1POPPE1Q1AC1(a) AE2Q2AC2(b) BMRDMC=MC1+MC2(c) OOQ

1950195119651967-19681965Kreps Wilson(1982)Fudenberg Tirole(1991)

123A B

-8-80-10-100-1-1

A B-8-100-1-8-100-1

-8-80-10-100-1-1

-

51449-100

MUDLRMR RLD DMLUM

10120301

0120

MSXLR

102201130122

12

A B

-8-80-10-100-1-1

MTMLRFBAR3C3

044053400453353566

5050-20004000400

5050-20004000400

-

04005050-200

50x+-201-x>0x2/3

100100-5000000

100100-5000000

--

AgentPrincipal

1000-5000300030001000-300015001500

Max X=fX SfX S[fX] CXU0

=RKLCKL d RKL/dK=d CKL/dK d RKL/dL=d CKL/dL d RL/dL=d CL/dL

d RL/dL=d RL/ dQ/d Q/ dL=MRMPL=MRPL 1 2VMPLVMPL VMPL =PMPL=MRPL

3 MR = P = MCX MPL P=MR VMP=MRP1 18 10 1802 16 10 1603 14 10 1408 4 10 40MRP/VMP0LMP MRP/VMP

3 MRP0LMRP MRP L TP MPL P MR VMP MRP1 10 --- 10.0 --- --- --- 2 19 9 9.5 8.9 * 85.5 80.53 27 8 9.0 7.8 72.0 62.54 34 7 8.5 6.6 59.5 46.0 5 40 6 8.0 5.2 48.0 31.0MRP=19*9.5-10*10=80.5 MR=MRP/MPP=80.5/9=8.9VMP=MPP*P=9*9.5=85.5

1 SL=MFCL =W

WSL=MFCL=AFCLW0LW.MFCMFCS=AFC=W0L2

W L TC MFC30 10 300 -- 32 11 352 52 34 12 408 56 36 13 468 60

1.,:W.VMPE S=MFC=W0VMP=MRP=DW00LL0

W0(MFC)=VMP(MRP)

2.,:W.MRPE S=MFC=W0MRP=DW00LL0

VMP

W0(MFC)=MRP

3.,

VMP(MRP)=MFC

C()MFCS=AFC=WVMP=DFEW00L0L

4.:

VMP(MRP)=MFC

C()MFCS=AFC=WVMPMRP=DW00L0EF

Da03.62.82SaDa1Da2Qa0Qa1Qa*0Dp01.31.00.8Sp0Dp*Sp1Qp0Qp*Qp10//ab

1. 2. (MRSAXY = MRSBXY)

OAEUA2

CHUA3

FUA1OBUB3

UB1

UB2

XYXYOAXYOBCXBYAXAYBUA1UA2UA3UB1UB2UB3E1E2E3X=XA+XB Y=YA+YB E

1. LK 2. (MRTSXLK = MRTSYLK)

LKLKLKLYLXKXKYOXOYE1E2E3CQX1QX2QX3QY3QY2QY1L=LX +LY K=KX +KY

4.

3. (Production contract curve)

0YXE1E2E3E4Y3Y2Y1X1 X2 X3YYXX

1.MRTXY = MRSXY 2. MRTXY < MRSXYYX3. MRTXY > MRSXYXY Y EM1Y1X1XO MRTXY < MRSXY Y/X Y/X

0.5/1 1/1 1/2 2/2

1 MRSAXY=MRSBXY 2 MRTSCLK=MRTSDLK 3 MRSXY=MRTXY

CDEOAOAOBA

Social Welfare Function

W{u1xu2xunx}=MAX{ u1xu2xunx}

3abc3xyzax > y > zby > z > xcz > x > y

Externalities

Q1OOQ*p1P*DMECMECS=MCMSCMCq1q* MSCp1(a)(b)DQ1Q*P1P*MECQ1DMSC=MC+MEC

MSB=D+MEB q*MSBMCq1q*

500800600

(public goods)(private goods)(nonexclusive)(nonrival)

(pure public goods)(quasi-public goods)(public resource)

ABRABOLONRAB OL+ON=OTEGHOCFQDODADBTNLTRMDbaDADB

FC\F*