teoria economica - formule
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7/16/2019 teoria economica - formule.
http://slidepdf.com/reader/full/teoria-economica-formule 1/2
Costul de oportunitate - y
xC
∆
∆−=0 ; TU=∑MU; MU=
01
01
TU TU
Q
TU
−
−=
∆
∆
; MU=TU’
Legea II Gossenn
n
y
y
x
x
P
MU
P
MU
P
MU === ... - Toeria cardinalista
Teoria ordinalista : Rata Marginala de Substitutie x
y MRS xy
∆
∆−= ;
MUy
MUx MRS xy =
Ecuatia liniei bugetului : I=X*Px+Y*Py ; Panta liniei bugetare y
x
P
P −
;
Echilibrul consumatorului in conditiile statice ;Y
Y
X
X
Y
X
Y
X
P
MU
P
MU SAU
P
P
MU
MU ==
Y
X xy
P
P MRS =
Comport.Prod. pe T.L.(Q=f(K,L)K- const,L- modif) : ;∑== MP QTP L L
TP AP L
L = ; L
TP MP L
L∆
∆= ;
)'( L L TP MP =
Rata Marg. de Subst. tehnol. K
L
LK
K
L
LK MP
MP MRTS
L
K
MP
MP SAU
L
K MRTS
K
L==>
∆
∆−=
∆
∆−=
∆
∆−= ;MRTSKL
(MRTS – arata de la cite unitati de K va refuza p-u a utiliza un factor de prod. suplimentar L)
Izocost L L KP LP TC += ; Cond. de echilibru. in cond. statice ; K
L LK
P
P MRTS
−
=
K
K
L
L
K
L
K
L
P
MP
P
MP SAU
P
P
MP
MP ==
TC= TFC+TVC = TFC+ L*W, unde L-nr.munc.,W-salariu ; Q= AP*L=> AFC=TFC/APL;
AVC= (L*W)/(AP*L)
Costul de prod. pe T.S.:TC=TFC+TVC; ;Q
TFC AFC = ;
Q
TVC AVC = ATC=AFC+AVC;
;Q
TC AC =
;QTC MC ∆∆= MC=TC’; Curba cost mediu LRAC : ;TC TRT −=Π MΠ=MR-MC; AΠ=AR-
AC;
Π=TR-TC; AΠ=P-AC; AΠ=Q
; Π=Q*AΠ;
Incasari: TR=Q*P; MR= ;Q
TR
∆
∆
AR=Q
TR; Rata Π: %100⋅
Π=
Π
K
T R ; %100⋅
Π=
Π
TR
T R ; %100⋅
Π=
Π
TC
T R
Pragul de rentabilitate: TC=TR; TC=P*Q; P= AVC Q
TC = ; TC=TFC+TVC; TVC=AVC*Q;
P*Q=TFC+AVC*Q <=>P*Q-AVC*Q=TFC; (P-AVC)*Q=TFC=> Q ;
AVC P
TFC
−cost.unitare =AC
AVC vor fi minime: AVC=MC;
Legea cererii: Qd=a-b*Px (a-const, volumul cons. p/u pretul 0, b- const, panta curbei cererii ).
Bun Giffen- bun inferioare Q↑P↑; Bun. Veblen – bun. de lux , dependenta directa
Legea ofertei: Qs=a’-b’*Px (a’-const autonoma, indica pretul de la care incepe oferta pe piata,b’-
panta cur ofertei)
Pret de echilibru:Qd=Qs; sau a-bPx=a’+b’Px. Incasarile bugetare Qe*Taxa.Povara fiscala P dupa impozitare- taxa si il compari cu 1Pret =>vinzator; p/u cump. cumparatori
P0 cu P1
Elasticitatea cererii : ;%
%
0
0
/ Q
P
P
Q
P
Q
E P D⋅
∆
∆−=
∆
∆−=
0
0'
/ Q
P
Q E D P D⋅−=
1
Cond.
optimala
7/16/2019 teoria economica - formule.
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Elasticitatea cererii prin punct :1
1
12
12
/Q
P
P P
QQ E
P D ⋅−
−−= ; Elast. Cererii prin arc
2/)(
2/)(
21
21
12
12
P P
P P
QQ E
P D+
+⋅
−
−−=
0
0
/%
%
Q
I
I
Q
I
Q E
I D ⋅∆
∆=
∆
∆= ;
0
0'
/Q
I Q E D I D ⋅= ; I D E / <0 – b.inferior; 0< I D E / <1- b.normal; I D E / >1- bun
de lux
)()(
%%
0
0
/ xQ y P
P Q
P Q E
y
x
y
x
y x ⋅∆
∆=∆
∆= ;)()(
0
0'
/ xQ y P Q E D y x ⋅= ; y x
E / <0-b.comp-re; y x
E / >0 –b.substi-le; y x
E / =0 –
autonome
;%
%
0
0
/Q
P
P
Q
P
Q E P S ⋅
∆
∆=
∆
∆=
0
0'
/Q
P Q E S P S ⋅= b=Q’d; b=Q’d=E*q/p
Volumul vinzarilor ;0
0
/Q
P
P
Q E P D ⋅
∆
∆−= din care ∆Q= - P D E
/ *∆P*0
0
P
Q, daca ∆Q=Q1-Q0, atunci
Q1-Q0= - P D E / *∆P*0
0
P
Q, respective Q1= - P D E / *∆P*
0
0
P
Q+Q0
Concurenta perfecta: Π=TR-TC; max Π= P MC MRQTC
QTR ===>=
∆
∆−∆
∆ 0 MC=TC’
Conditie de echilibru pe TL: P=MC=ACmin=LRACmin (volumul optim de prod ) Nr. de firme=
Q/q
Monopol MC=MR, P>MR; pd E
MC P
/
11−
=
, pd E
/ - elast. cererii la produsele firmei
Lerner(put.de monopol) ; P
MC P L
−= ;
1
/ pd E L = Taxa cump-tor+;Π=AΠ*Q; AΠ=P-MC, AΠ-
pr.unitar; AR=P
Monopolista . Cond. de echilib. AC=P; MR=MC; Echil.in PL Π=0; LRMC=MR;
Surp.Capacitatilor=Qc.p-Qc.m
Oligopol Vol.prod (q*=q1+q2); TR1=q1P=q1f(q1,q2); TR2=q2P=q2f(q1,q2); Π1=TR1(q1,q2)-
TC1(q1);
P=a-bQ; Q=q1+q2; P=a-b(q1+q2).
Daca TR=Pq, iar TC=k+cq, k-cost fixe, cq-costuri medii: Π1=Pq1-k1-c1q1
Profitul va fi maxim : 02 121
'
1 =−−−=Π cbqbqa ; acbqbq =++ 1212 ; 1212 cbqabq −−=
Vol. de echil. ;22
21
1
q
b
caq −
−= ;
22
2 1
2
q
b
caq −
−=
Daca firme cu costuri identiceb
caq3
*
1−
=
MC=MR, MR=TR’. TR=P*Q, Q=q1+q2; Π1=q1*(P-MC) Πcartel=Q*(P-MC); Πfirma=Π
cartel/2
Vol. optim de productie ale firmei :lider -b
caq
2
*
1
−= ; firma satelit
b
caq
4
*
2
−=
Profitb
ca
8
)( 2
1
−=Π firma lider;
b
ca
16
)( 2
2
−=Π - firma satelit
2