Θεωρία Κινδύνου

73
1 ΠΑΝΕΠΙΣΗΜΙΟ ΠΑΣΡΩΝ ΥΟΛΗ ΘΕΣΙΚΩΝ ΕΠΙΣΗΜΩΝ ΣΜΗΜΑ ΜΑΘΗΜΑΣΙΚΩΝ ΜΑΘΗΜΑΣΙΚΗ ΔΙΑΥΕΙΡΙΗ ΚΙΝΔΤΝΟΤ ΔΙΠΛΩΜΑΣΙΚΗ ΕΡΓΑΙΑ ΠΑΝΑΓΙΩΣΑ Γ. ΞΕΠΑΠΑΔΑΚΗ ΜΑΘΗΜΑΣΙΚΟ ΠΑΣΡΑ 2009

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ΑΝΑΛΟΓΙΣΤΙΚΗ ΜΕΛΕΤΗ

Transcript of Θεωρία Κινδύνου

  • 1

    .

    2009

  • 2

    , .

    , , .

    , , , .

  • 3

    1.

    2.

    1:

    1.

    1.1

    1.2

    1.3

    1.3.1 VaR

    1.3.2 (Expected Shortfall)

    1.4

    1.4.1

    1.4.2 VaR

    1.4.3

    2:

    2.1 (Market Risk)

    2.1.1 -

    2.1.2

    2.1.3 Monte Carlo

    2.2 (Operational Risk)

    2.2.1

    2.2.1.1 (BI)

    2.2.1.2

    2.2.2

    3: (Credit Risk)

    3.1

    3.1.1 Merton

    3.1.2 Merton

    3.1.3

    3.1.4

    3.1.5

    3.1.6 KMW

    3.1.7

    3.1.8

  • 4

    3.2

    3.2.1

    3.2.2

    3.3

    3.3.1 Bernoulli

    3.3.2 Poisson

    3.3.3

    3.3.4

    3.4 Monte-Carlo

    3.4.1

    3.4.2 Bernoulli

    3.4.3 Bernoulli

    4:

    4.1

    4.1.1 VaR

    4.2

    4.2.1

    4.2.2 Euler

    4.2.3 Euler

    5:

    5.1 Fsn

    5.2 Poisson

    5.3 -

    5.4 Panjer

    5.5 Poisson

    5.6 Poisson

    5.7 Poisson

  • 5

    1.

    20 . 1950

    .

    Hanry Markowitz 1952

    . ,

    -

    .

    1970.

    :

    i)

    .

    ii)

    .

    2.

    1970 1988

    (Bassel I).

    :

    .

    ,

    .

    . 2001 ,

    (Bassel I), .

    , ,

    :

  • 6

    i) : .

    ii) : .

    iii) : .

  • 7

    1 :

    1.

    1.1

    (, F, P)

    .

    1.1: ,

    S

    V(s).

    1.2:

    [S, S+] :

    SSss VVL , ,

    .

    1.3: ssL ,

    .

    ,

    .

    ,tY t tYY1 .

    ttttt VVLL 11,1

    tZttFV , (1.1),

    t d- dtt ZZ ,1, ,..., ,

    F dx .

    (1.1) .

    ,tX t

    1ttt ZZX ,

    ttt ZtXZttFFL ,),1(1 1

  • 8

    1.4: t d

    tt ZtXZttFFx ,),1( , dx

    )( 11 ttt XL .

    F , -

    d

    iittZttt XZtfZtFL i

    1

    ,11 ),(,

    L - .

    1.5: :

    d

    i

    itZttt XZtfZtFx i1

    ),(,

    .

  • 9

    1.2

    .

    .

    1tL t

    F F

    tF - Boole. :t sx s tF , -

    Boole

    (). 1tx t

    F F 1tx

    tF .

    1tL t

    F F :

    11 1( ) ( )

    t tt t t tL F tF P x P L F

    1tL

    F

    xF d . ,tX t

    .

    1 1 1( ) ( )

    tL t ttF P x P L

    ,

    .

  • 10

    1.3

    .

    :

    )

    )

    )

    ) .

    . -- (VR)

    (Expected Shortfall).

    1.3.1. VR

    --

    .

    , :

    ( ) ( )LF P L (1.3.1)

    LF

    .

    :

    : ( ) 1LinF F

    LF

    .

    1.3.1 (--).

    0,1 . -- ,

    ,

    L (1-).

    : ( ) 1 : ( )LV R inF P L inF F (1.3.2)

  • 11

    0,95 0,99 1 10

    .

    VR

    (1-).

    VR .

    1.3.2 ( )

    i) :T ,

    T :

    ( ) : ( )T y inF x T x y

    .

    ii) F , F

    F .

    0,1 - F

    : ( )q F F inF x F x

    1.3.1 0x - F

    :

    i) 0( )F x ii) ( )F x

    1.3.2. (Expected Shortfall)

    1.3.2 ( ). L E L

    LF ,

    0,1 :

    11

    1 u LES q F du (1.3.2)

    ( )u L Lq F F u LF .

    :

    11

    1 uES V R L du

  • 12

    , VR

    u .

    ES L . ES V R .

    1.3.2 L

    LF 0,1 , :

    ( ; ( ))( )

    1

    E L L q LES E L L V R (1.3.3)

    ( ; ) ( )AE X A E XI

    X .

    1: LF (1.3.3)

    :

    1( ; ) (1 )

    1ES E L L q q P L q (1.3.4)

    1.3.3 i iL

    LF :

    1

    ,

    1lim[ (1 )]

    n

    i ni

    n

    L

    ESn

    (1.3.5)

    1, ,n n nL L 1, , nL L [ (1 )]n

    (1 )n .

    ES

    VR. ,

    VR.

    .

  • 13

    1.4

    (coherent risk)

    1.4.1

    (, F, P) .

    L0 (, F, P) (, F)

    .

    L0 (, F, P)

    .

    .

    ) L1 L2 , L1+L2

    ) L1 L1 >0

    : R.

    (L)

    L,

    .

    (L) 0 .

    : R

    , :

    1 ( ) L

    (L+) = (L)+

    2 () L1, L2 (L1+L2) (L1) + (L2)

    3 ( ) L >0 (L) = (L)

    4 () L1, L2 L1L2, (L1) (L2)

  • 14

    1.4.1 ( )

    ,

    , ( ) .

    1.4.2 VR

    d=100 .

    .

    (2%).

    100 .

    , 1t 105,

    .

    Li i-, 100 -5

    i i-.

    i 1 [ , 1]t t

    .

    Li = 100Yi -5(1 - Yi) = 105 Yi 5

    Li

    P(Li = -5) = 0.98 P(Li = 100) =0.02.

    . 10.000.

    100 100 .

    .

    VR.

    VR 95%

    .

    : LA = 100L1 VR0.95(LA) = 100VR0.95(L1)

    P(L1-5) = 0.98 0.95 P(L11) = 0 < 0.95 l

  • 15

    VR0.95(LA) = -500

    500

    VR

    95%.

    . 100 100

    1 1

    105 500B i iIi Ii

    L L Y

    100

    1

    ( ) 105 500a B a iIi

    VaR L q Y

    100

    1

    B (100, 0.02)ii

    M Y

    P(M5) 0.984 0.95 P(M4) = 0.949 < 0.95

    0.95( ) 5q M

    0.95( ) 25BVaR L .

    125

    VR 95%.

    .

    .

    VR .

    , :

    100 100

    1 11 1

    ( ) 100 ( ) (100 )i ii i

    P L P L P L P L

    , ,

    .

    --

    .

    1.4.2 ( VR

    )

  • 16

    X ~ Ed (,,)

    01

    : , d

    i i ii

    M L L X R

    L1, L2 M 0.5 < 1

    1 2 1 2( ) ( ) ( )V R L L V R L V R L

    1.4.3

    1.4.3. .

    : ,

    11

    ( )1

    ES V R L duu

    .

    :

    L1, , L1 L1,n

    Ln,n m 1 m n :

    1, 11

    sup : 1 i ...m

    m

    i n i i mi

    L L L i m

    L L F

    1 1( , ), . . . , ( , )

    n nL L L L F.

    ( , ) + i i iL L L L ,( + ) i nL L 1( + ) , , ( + ) nL L L L :

    1, 11

    ( ) sup ( ) ... ( ) : 1 ...m

    m

    i n i i mi

    L L L L L L i i m

    1 1

    sup ... : 1 ...mi i m

    L L i i m

    1 1sup ... : 1 ...

    mi i mL L i i m

    , ,1 1

    m m

    i n i ni i

    L L

  • 17

    m = n(1-) n, ( ) ( ) ( )ES L L ES L ES L

  • 18

    2 :

    2.1. (Market risk)

    (.. ,

    , , ) .

    .

    2.1.1

    1tX

    :

    1 ( , )t dX N

    .

    1 [ ] 1( )t t tL X .

    :

    [ ]( ) ( )t t tx c b x (2.1.1)

    tc tb

    t.

    1tX .

    :

    1 [ ] 1( ) ( , )t t t t t t tL X N c b b b (2.1.2)

    ,

    1, ,t n tX X .

    ,

    -

  • 19

    .

    1 1 1( , )t t d t tX F N

    1t 1t - .

    .

    . ,

    .

    2.1.2

    .

    [ ] 1( )t tL X

    1, ,t n tX X . ,

    .

    [ ]( : 1,...,s t sL X s t n t (2.1.2)

    sL

    s.

    .

    xF

    xF .

    1, ,t n tL L

    [ ]( )t X xF .

    .

    .

  • 20

    2.1.3 Monte-Carlo

    1, ,t n tX X .

    .

    m-

    , :

    (1) ( )1 1, ,

    mt tX X

    :

    ( ) ( )1 [ ] 1( : 1,...,

    i it t tL X i m

    1tX ,

    .

  • 21

    2.2. (Operational Risk)

    , (, )

    .

    2.2.1

    :

    i) () ii) .

    2.2.1.1 ()

    ,

    .

    ,

    .

    t

    :

    3

    1

    1( ) max( ,0)t t iBI

    t i

    RC OR IZ

    3

    01

    t it Ii

    Z I

    t iI t i

    15% .

    2.2.1.2

    8 :

    , , ,

    , , , ,

    .

  • 22

    .

    :

    3 8

    1 1

    1( ) max ,0

    3

    t t is j j

    i i

    RC OR I

    , t i

    j

    .

    .

    2.2.2

    ,

    : ,

    , , -

    , ,

    , -

    .

    t.

    :

    , . , ,: 1,..., ; 1,...,8; 1,...,7; 1,...,t i b t i bX i T b N

    , .t i bX -

    b t i .

    , ,t i bN :

    T : ( 5T )

  • 23

    b

    t i :

    , ,7, , ,

    1 1

    t i bNt i b t i b

    k

    L X

    t i :

    , ,8,

    1 1

    t i bNt i t i b

    k

    L L

    tL t

    VR

    .

    ( ) ,

    :

    ( )t tAMRC OR L

    = 0,99 -0,999.

    ,

    :

    8,

    1

    ( )t t bAMb

    RC OR L .

  • 24

    3 : (Credit Risk)

    .

    ,

    , .

    -.

    Merton (1974),

    ,

    .

    ,

    .

    . -

    .

    -.

  • 25

    3.1

    .

    . ( tX )

    tX

    0t .

    3.1.1 Merton

    tV

    .

    Merton :

    T. t

    St Bt . (

    ).

    .

    Vt=St + Bt, 0 t T .

    ,

    .

    :

    i) TV B ,

    .

    St = Vt B.

    .

    ii) TV B ,

    . ,

  • 26

    .

    , T TB V , ST = 0.

    :

    max ,0T T TS V B V B (3.1)

    min ,T T TB V B B B V (3.2)

    Merton (Vt) Brown

    :

    t t t tdV V dt V dW

    , 0 Brown ( tW ).

    20

    1exp

    2T TV V T W

    2 20

    1ln ln ,

    2TV N V T T

    :

    20

    1ln( / )

    2ln lnT T

    B V T

    P V B P V BT (3.4)

    .

    3.1.2 Merton

    Merton

    Vt

    .

    (3.1.1)

    i)

    ii) 0

  • 27

    iii)

    .

    Th V , (3.1)

    (3.2) (3.1.1).

    ( , )tF t V

    t T .

    . F(t,Vt) (PDE)

    F(t,u) :

    2 21, , , ,2

    t y uu uF t u u F t u ruF t u rF t u 0,t T (3.5)

    f(t,u)=h().

    (3.5) Black- Scholes.

    . F(t,Vt) Q

    ( , )tF t V

    Q. Q Vt

    :

    t t t tdV V dt V dW (3.3)

    W W Q Brown (

    ).

    :

    ( )( )( , ) T

    Q r T tt V tF t V E e h F (3.6)

  • 28

    3.1.3

    PDE (3.5)

    (3.6) Black-Scholes CBS.

    t :

    ( )

    ,1 ,2

    2

    ,1 ,2 ,1

    ( , ; , , , ) ( ) ( )

    1ln ln ( )

    2

    BS r T tt t v t t t

    T v

    t t t v

    v

    S C t V r B T V d Be d

    V B r T t

    d d d T tT t

    (3.7)

    2 201

    ln (ln , )2T v v

    V N V r T T

    t=0 , :

    2

    0

    0,2 0,2

    1ln ln

    2( ) 1 ( )

    T v

    T

    v

    V V r T

    Q V B Q d dT

    (d)=1-(-d) 1-(d0,2) .

    1-(dt,2)

    t.

    3.1.4

    (ii) (3.11) -

    tT

    0( , ) exp( ( ))t T r T t

    (3.2) :

    0( , ) ( , ; , , , )BS

    t t vB B t T P t V r B T (3.8)

  • 29

    ( , ; , , , )BS t vP t V r B T Black-Scholes strike B

    ( )tV r .

    ( )

    ,2 ,1( , ; , , , ) ( ) ( )BS r T t

    t v t t tP t V r B T Be d V d (3.9)

    ,1td ,2td (3.7).

    (3.8) (3.9) :

    0 ,2 ,1( , ) ( ) ( )t t t tB t T B d V d (3.10)

    3.1.5

    (3.10)

    C(t,T). -

    P0(t,T) P1(t,T)

    .

    11 0

    0

    ( , )1 1( , ) ln ( , ) ln ( , ) ln

    ( , )

    P t TC t T t T T t

    T t T t P t T (3.11)

    Merton 11

    ( , ) tP t T BB,

    ,2 ,1

    0

    1( , ) ln ( ) ( )

    ( , )t

    t t

    VC t T d d

    T t B t T (3.12)

    20( , ) 1ln ( )2

    ( ,1)v

    t

    v

    B t TT t

    Vd t

    T t dt,2

  • 30

    T-t, C(t,T) v

    0( , )

    t

    B t Td

    V.

    3.1.6 KMV

    Merton

    KMV 1990.

    KMV .

    KMV

    EDF. EDF

    KMV.

    (3.4) =1 (d)=1-(-d)

    2

    0

    1ln ln

    21

    v v

    Merton

    v

    V B

    EDF (3.13)

    KMV EDF Merton.

    Merton

    .

    (3.13).

    (DD)

    0

    0

    ( )

    v

    V BDD

    V (3.14)

    B V0 .

    3.1.7

    .

  • 31

    :

    , :

    Table 8.2: Probabilities of migrating from one rating quality to another within one year.

    Source: Standard & Poors CreditWeek (15 April 1996)

    .

    , S&P

    .

    , CCC

    .

    [0,]. ( ), 0 j np j

    .

    j

    . (0)p

    .

    t v t v t tdV V dt V dW

  • 32

    20

    1exp

    2T v v v TV V T W

    .

    0 1 1... n nd d d d

    1( ) ( )j T jP d V d P j {0,..., }j n .

    .

    1d .

    VT jd .

    :

    2

    0

    1ln ln

    2T v v

    T

    v

    V V T

    XT

    20

    1ln ln

    2j v v

    j

    v

    d V T

    dT

    j 1j T jd X d .

    3.1.8

    .

    Merton.

    m-

    Vt Vt = (Vt,1,, Vt,m)

  • 33

    m- Brown v = (v1,, vm)

    v = (v1,, vm) .

    i VT,I

    2

    0

    1exp

    2T v v v TV V T W

    v= vi , v= vi WT=WTi

    H WT=(WT,1,WT,m) WT~Nm(O,TP)

    0 1 1... n nd d d d

    .

    3.2

    (Threshold)

    .

    i

    x,i di

    [0,].

    x=(x1,,xm).

    x.

    3.2.1

    m-

    .

    1 i m , Si i

    ,

    Si = ST,i

    0,1,...n .

  • 34

    t=0, -.

    1( ,..., )mY Y Y

    1 1( ) ,..., , 0,1m

    m mp y P Y y Y y y

    .

    ( 1), 1,...,i iP P Y i m .

    :

    2 2

    ( , )( , )

    ( )( )

    i j i ji j

    i i j j

    E y Y P Pp y Y

    P P P P (3.4.1)

    2 2 2 2

    i i i i i i iY E Y P E Y P P P .

    1

    m

    ii

    M Y .

    :

    1

    m

    i i ii

    L eY

    ei i 0i 1

    .

    S Y.

    S

    Y, .

    S :

    1 (1) ( )( , , ) ( , , )d

    m mS S S S

  • 35

    (1) ( )( ,..., )m (1,..., )m .

    1,..., 1m m

    -

    S .

    :

    ( 1), 1,...,iP Y i m : .

    ( 1,..., 1)i iP Y Y , 1, , 1,..., ,2i i m m

    -.

    :

    2 1i i iE Y E Y P Y

    21, 1i j i jE YY P Y Y

    2

    2,i jY Y

    22

    2, ,y i jP P Y Y i j

    3.2.2

    3.2.2: 1( ,..., )mX X X m-

    mxnD dij i ,

    i 1

    ...ni i

    d d .

    1i

    d ( 1)ni

    d

    ( 1)j ji i i iS j d X d , 0,..., , 1,...,j n i m

  • 36

    (X,D) 1( ,..., )mS S S .

    x

    ( ) ( )i iF x P x x .

    i- D - i.

    , ( Si=0)

    1i iX d i :

    1( )i i ip F d .

    ( , )i jP Y Y i j

    ( Xi Xj).

    ( , )i jP Y Y (1)

    1 1

    ( ) ( , )i j i i j jE YY P X d X d .

    , Xi Xj

    .

    .

    , .

    .

    : d-

    [0,1]d .

  • 37

    1( ) ( , , )dC u C u u

    .

    C : [0,1] [0,1]dC

    :

    1) 1( , , )dC u u iu

    2) (1,1,...,1, ,1, ,1)i iC u u 1,..., , [0,1]ii d u

    3) 1 1( , , ),( , , ) [0,1]d

    d db b i ib :

    1

    1

    2...

    1

    1 1

    ... ( 1) ( ,..., ) 0dd

    d

    i ii di

    i i

    C u u

    1j j

    u 2j j

    u b 1,...,j d .

    (Sklar 1959). F 1, , dF F .

    : [0,1] [0,1]dC , 1, , dX X

    ,

    1 1 1( , , ) ( ),..., ( )d d dF X X C F X F X (4.3)

    , ,

    1 1 1...x x dRanF RanF RanF ( )i iRanF F R

    1F . , C 1, , dF F

    , F (i)

    1, , dF F .

    : 1( , , )dC u u Frchet:

    1

    1

    max 1 ,0 ( ) min , ,d

    i di

    U d C u u u

  • 38

    : F 1, , dF F :

    1

    1

    max ( ) 1 ,0 ( ) min ( ), , ( )d

    i i di

    F x d F x F x F x

    F .

    S .

    3.2.2: ( , )X D ( , )X D

    1( ,..., )mS S S 1( ,..., )mS S S .

    :

    i. S S .

    ( ) ( )i iP S j P S j , 0,..., , 1,...,j n i m

    ii. X X C

    .

    -

    1, , 1,...,i i m 1,...,i ip p . :

    1 1 1 1 11 1 ,...,1,..., 1 ,..., ( ,..., )i i i i i i i i i ip Y Y P X d X d C P P ,

    1,...,i i

    C - C .

    . X

    Y . :

    1,..., ,..., ,2C m

    .

  • 39

    3.3 - -

    ()

    .

    3.3( Bernoulli): p m p-

    1( ,..., ) ,

    1( ,..., )mY Y Y Bernoulli ,

    : 0,1iP , 1 i m , ,

    Bernoulli

    :

    1( ) ( )i iP Y P

    y y y1( ,..., )m 0,1m

    :

    y1

    1( ) ( ) (1 ( ))i i

    my y

    i iiP Y P P

    3.4 ( Poisson): p

    , 1( ,..., )mY Y Y Poisson

    , : 0,i , 1 i m

    Y Poisson

    i .

    1

    m

    ii

    M Y , Poisson i ,

    M .

    !

    1

    1

    ( )

    ( ) exp ( )

    m

    imi

    ii

    P M

  • 40

    3.3.1 Bernoulli

    ..

    ( ) : 0,1iP

    , ,

    Bernoulli

    1( ) ( )i iP Y P

    :

    . Bernoulli

    iP .

    Bernoulli .

    1( )Q p

    P)S( .

    Q q , m

    Bernoulli q

    q m.

    (1 )mm

    P M Q q q q

    :

    (1 ) q)mm

    P M q q dS(

    .

    Bernoulli

    .

  • 41

    iX ,

    ( )ip

    ( ) ( )i ip h x

    : (0,1)h

    ( ) ( )h x x 1

    ( ) 1 exp( )h x x , =(1,,)

    , .

    3.3.2 Poisson

    Credit Risk Poisson.

    i Poisson i

    :

    i i ik w

    0ik , 1,...,

    pi i iW W W 1ij

    j

    W

    p ( , )j jS 1,...,

    2j j j 0j .

    1jE

    2

    j j ( ) ( )i i i iE k E W k .

    :

    ( 1) ( 0) ( 0 )i i iP Y P Y E P Y

    iY Poisson :

    ( 0 ) (1 exp( )) ( )i i i i i iE P Y E kw k E W k

    Poisson, 1

    m

    ii

    M Y

    Poisson

  • 42

    1

    ( )m

    i ii

    M Poi k w

    M Poisson

    , , S

    ( , ( 1))bN N .

    p, M p

    , :

    1 1 1 1 1

    ( )p pm m m

    i i i ij j j i iji i j j i

    k w k w k w

    ,...,i pM M

    jM

    Poisson 1

    ( )m

    i ij ji

    k w , j j .

    1,..., jM

    ,

    :

    1

    pd

    jj

    M M

    1

    ( )m

    i ij ji

    k w ,

    jM .

    3.3.3

    Bernoulli.

    .

    .

  • 43

    i ie , i iY

    i i

    (0,1]

    .

    m :

    ( )

    1

    mm

    ii

    L L i i i iL e Y

    :

    (1) p- : 0,1pi

    , , i iL

    :

    ( )i iE L

    (2) : p

    ( )

    1

    1 1lim lim ( )

    mm

    im mi

    E Lm m

    p .

    .

    (3) c 2

    1

    mi

    i

    ec

    i m.

    3.5.3: ( )

    1

    mm

    ii

    L L

    1, 2, 3. ( )P

    i iL

    .

  • 44

    ( )1lim mm

    Lm

    3.3.3: ( )

    1

    mm

    ii

    L L

    1, 2, 3 S .

    S q , . , 0q S .

    :

    ( )1lim ( ) ( )mm

    q L qm

    .

    Bernoulli,

    .

    3.3.4

    Bernoulli. :

    i. Bernoulli Monte Carlo.

    ii. .

    iii. Bernoulli

    .

    Bernoulli .

    3.3.4 : p-

    p m p-

  • 45

    1( ,..., ) , , 1, , mX X

    .

    3.3.4: (, ) m-

    . p- ,

    1i i

    i x dY I Bernoulli

    , :

    1( ) ( )i i ip P X d

  • 46

    3.4 Monte Carlo

    3.4.1

    X , , ,F P ,

    f.

    ( ) ( ) ( )e h x h x f x dx (3.4.1)

    h.

    ( ) x Ah x I A .

    (3.4.1)

    X , Monte Carlo.

    f.

    3.1: (Monte Carlo intergration)

    (1) 1, , nX X f.

    (2) Monte Carlo 1

    1( )

    MC n

    n ii

    h Xn

    Monte Carlo

    ( ).

    g

    r(x) :

    ( ), ( ) 0

    ( ) ( )

    0, ( ) 0

    f x g x

    x g x

    g x

    r

    :

  • 47

    ( ) ( ) ( ) ( ( ) ( ))gh x r x g x dx E h X r X

    :

    3.2: ( )

    (1) 1, , nX X g.

    (2) IS : 1

    1( ) ( )

    IS n

    n i ii

    h X r Xn

    .

    IS Monte Carlo.

    :

    2 2 21var ( ) ( )IS

    ng gE h x r xn

    2 21var ( )MC

    ng gE h xn

    2 2( ) ( )gE h x r x

    2( )gE h x .

    ,

    IS

    n

    g.

    - h .

    ( ) ( )( )

    ( ( ))

    f x h xg x

    E h x (3.4.2)

    ( ( ))

    ( )( )

    E h xr x

    h x

    1 1 1( ) ( ) ( ( ))IS

    h x r x E h x .

    IS (3.4.2)

    ( ( ))E h x .

    (3.4.2) IS .

  • 48

    IS

    X .

    t :

    ( ) ( ) ( )txxM t E e f x dx

    x, .

    ( )xM t , IS :

    ( ) ( ) ( )txt xg x e f x M t

    ( )

    ( ) ( )( )

    txt x

    t

    f xr x M t e

    g x

    t x.

    ( exp( ))( )

    ( )t t x

    E x txEg x

    M t

    t , :

    ( ) : ( )tx

    xx cE r x x c E I M t e (3.4.4) .

    tx tce e x c 0t , :

    ( ) ( )tx tcx xx cE I M t e M t e

    (3.4.3) t ,

    t .

    , t ln ( )xM t tc .

    (3.4.3) :

    ( exp( ))ln ( )

    ( )x tx

    d E x txM t tc c c

    dt M t.

    3.4.2 Bernoulli

    )

    0,1m

    1Y .

  • 49

    :

    1

    1( ) (1 )i i

    my y

    i iiP Y P P , 0,1

    my

    iP .

    L :

    1 11

    ( ) (exp( )) ( ) ( 1 )i i im m m

    teY teL i i i ii i

    i

    M t E t eY E e e P P

    Q(t) : ;( )

    tL

    t p

    t

    eQ y E Y y

    M t,

    1 1

    1

    expexp( )

    (1 )( ) exp( ) 1

    i i

    m

    i i mi y yi i

    t i iit i i

    t eYteY

    Q y P y P PM t te P P

    ,exp( )

    exp( ) 1i i

    t i

    i i

    te Pq y

    te P P.

    1

    , ,1

    (1 )i im

    y yt t i ti ii

    Q y q q , tilting

    ,t iq .

    ,t iq 1 t , t .

    )

    :

    ( ) ( )P L c .

    .

    :

    3.3: (IS )

    (1) ip

  • 50

    1

    exp( ) ( )

    exp( ) ( ) 1 ( )

    mi i

    ii i i i

    te Pe c

    te P P

    ( , )t t c tilting.

    (2) n1 1,..., mY Y .

    ,

    i-:

    ( , )

    ( , )

    exp( ) ( )

    exp( ) ( ) 1 ( )

    c i i

    c i i i

    t e P

    t e P P

    (3) 1

    ( , ) exp( ) ( ) 1 ( )m

    L i i iiM t te P P

    L.

    n1 1

    m

    i ii

    L eY 1( )(1), , nL L .

    IS :

    1

    ,1

    ( , ) ( , )11

    1( ) ( , ) exp

    j

    IS nj

    n L c cL cj

    M t I t Ln

    ) IS

    Bernoulli

    Gauss ( )ip (0, )pN .

    ( , )pN

    p .

    ,

    .

    ( )r :

    1

    1 1

    1

    1exp ( )

    12( ) exp

    1 2exp ( ) ( )

    2

    r

  • 51

    IS

    3.4: ( IS Gauss)

    (1) 1, , ( , )n pN I

    (2) i 1

    ,1

    ( )IS

    n i 1.

    (3) IS :

    1

    ,1

    1

    1( )

    IS ISn

    n ni ii

    rn

    : .

    1

    ,1IS

    n P L C , IS

    P L C

    IS g

    11( ) ( )exp2

    g P L c

    .

    ,

    P L C .

    g IS .

    ,

    :

    11max exp2

    P L c

  • 52

    3.4.3 Bernoulli

    1,...,t n , tm

    t tM

    .

    Qt (0,1), tM

    . ,t t q tM Q B m q .

    1 2, .

    )

    1 t n ,1 ,,..., tt t mY Y tm .

    1

    1

    , ,( ,.., ) (1,..., )

    ,...,t

    tt i t i

    i i m

    MY Y

    t .

    t tM mE

    t tM mE

    ,

    n-.

    1 1

    ( 1)...( 1)1 1( 1)...( 1)

    t

    n nt t t

    t tt t t t

    M

    M M M

    mn n m m m

    =1 :

  • 53

    1

    1n

    t

    t t

    M

    n m

    :

    2

    2

    2

    )

    Qt .

    , .

    tm t , tM -

    :

    1 1 1

    0

    ,1( ) (1 )

    ( , ) ( , )m b

    b mm mP M q q dq

    b b

    :

    1

    ,( , , )

    ( , )

    nt t tt

    t t

    M b m MmL b data

    M b

  • 54

    4 :

    - .

    ,

    , .

    4.1

    .

    Frchet.

    Frchet.

    1( ,..., )dL L L ,

    ,

    : d .

    ( )L .

    ( )L .

    .

    ((L)),

    ( )L

    L .

    4.1: iF , 1,..,iL i n

    .

    , :

    min ((L)) max

    maxp .

    (4.1) (4.1)

    .

  • 55

    inf : , 1,...,

    sup : , 1,...,

    i i

    i i

    p L L F i d

    p L L F i d

    (4.2)

    1,..., dF F (~)

    .

    4.1 1 VR

    = VR.

    VR(((L))

    iF , 1,..,iL i d .

    iL , .

    4.1.1 (comonotonicity). 1,..., dX X

    comotonic Frchet

    1 1( , , ) min , ,d dM u u u u .

    4.1.1: 0 1 1,..., dL L comotonic

    .

    1 1... ( ) ... ( )d dV R L L V R L V R L .

    F L.

    Fi,

    C : F=C(F1,,Fd)

    1,..., dL L C.

    W C M

    W M Frchet .

    :

  • 56

    (2) oC C oC

    1,...,d

    dX X X 1 1 1,..., , ,i i i dX X X X X .

    1d

    dX ( ) sup : ,x d d d ds x X x s

    s .

    c d , s :

    , 1 ( )( , , )c d s cF F L S

    1 1

    , 1 ( ) 1 1 1 1,...,

    ( , , ) sup ( ), , ( ), ( )d

    d

    c d s d d d xx x

    F F C F x F x F s

    ( )dF x dF x .

    :

    ( ) inf : , 1,...,i im s P L s L F i d

    , 1 ( )( , , ) :c d s dF F c C

    dC - .

    4.1.1 ( )

    L 1( 2)d d 1,..., dF F copula C.

    oC oC C .

    : d , s

    , 1 ( ) , 1 ( )( , , ) ( , , )c d s c d sF F F F (4.1.1)

    , :

  • 57

    1

    max , ( ) , ,1( )

    min ,...,

    d

    ot

    d

    t C u u tC u

    u u

    , 1 ( )( ,..., )oC d st F F (4.4.1)

    , 1,max ( ,..., )oC dV R F F

    . (4.4.1) :

    ,maxV R L V R

    0 1 , (4.1).

    (4.1.2) ( )

    F 1 dF F F .

    0S 1F F .

    ( 1)

    0,( ) 1 ( )

    s d r

    rr s dm s d inF F x dx

  • 58

    4.2

    4.2.1

    d

    1,..., dL L .

    .

    :

    . (L), 1

    d

    ii

    L L

    .

    .

    . (L)

    .

    .

    ,

    1,..., dL L (C1,,ACd).

    (L) =1

    d

    ii

    AC

    .

    1,..., dL L , , ,F P ,

    d .

    \ 0d .

    , 1

    ( )d

    i ii

    L L .

    M

    ( ) :L .

  • 59

    : ( ) ( )Lk k

    ( )k

    .

    4.2: k \ 0d ,

    1 . :r d

    , :

    ( )

    1

    ( ) ( )d

    ri i

    i

    k

    k (4.2)

    ( )r

    i

    iL , ( )L .

    i iL ( )r

    i i

    (4.2) ( )

    .

    4.2.2 Euler

    ,

    .

    , :

    ( ) ( )t tk k , 0,t

    ( ) : k

    .

    Euler, k

    , :

    1

    ( ) ( )d

    iii

    rkk (4.2.2)

    (4.2) (4.2.2) .

  • 60

    4.2.2: ( Euler)

    ,

    , Euler :

    :r dk , ( ) ( )

    r

    i

    rk k

    (4.2.3)

    Euler :

    ( ) ( )r

    rk k .

    4.2.2 ( )

    ( ) ( ( ))SDr v r L

    1,..., dL L .

    12( )SDr

    1

    cov( , )cov( , ( ))

    ( ) ( )( ) var( )

    SD

    d

    i j jr jSD i

    iSD

    L Lr L L

    r L

    =1, i-

    :

    cov( , )(1) , (1)

    var( )

    SDr ii i

    L LAC L L

    L

    4.2.2 : :

    ,

    . (0, , )dL E ( ). ,

    Euler, :

  • 61

    1

    1

    (1)

    (1)

    d

    ri

    i ir d

    jj

    j

    AC

    AC

    k

    k , 1 i j d (4.1.9) (4.2.4)

    4.2.3 Euler

    4.2.3: k , ,

    r .

    r

    , , :

    0,( )( ) ( )

    ( )0,

    ( )( )

    i i

    r

    i i i

    r

    E L E L

    rE L

    r E L E L

    r

    k

    k

    k

    k

    k

    i

    r

    i ,

    i i

    .

    4.2.3 : 4.2.3

    Euler.

    .

    1

    ( ) ( )d

    ii

    L Lk k ,

    .

    ,

    ( )i iAC Lk .

  • 62

    4.2.4: ,

    , r

    ,

    0,1d

    , .

    1 1

    1

    ( ) ( ,..., )d

    ri i d di

    i

    rk k (4.2.5)

    (4.1.3),

    (4.2.5) =1.

    ,

    , 1

    ( )d

    i ii

    L L .

    :

    1 c

    d

    i i i i i ii i i

    L L L

    k k k

    .

  • 63

    5 :

    ,

    .

    .

    5.1 NSF

    5.1: ( )

    N(t) 0,t

    1 2, ,X X . :

    ( )

    ( )

    1

    N t

    N tS X (5.1)

    ( )( ) ( )NS N tF x P S x

    .

    , NS NSF .

    NS

    F

    ( )x .

    5.1 (, )

    x

    , (0) 0 . ( )x

    , (5.1)

    . ( ) ( )Np P N ,

    0,1,2,... . .

  • 64

    5.1 ( ) : NS ,

    5.1, 0x :

    ( )

    0

    ( ) ( ) ( ) ( )NS N

    F x P S x x (5.2)

    ( )( ) ( )Kx P S x - .

    (0)( ) 1x

    0x (0)( ) 0x 0x .

    (5.2) ,

    .

    .

    :

    0

    ( ) ( )sxF s e dF x , 0s

    Laplace-Stieltjes, ( )( ) ( )s s .

    :

    0

    ( ) ( ) ( ) , 0 NS N N

    F s P s M s s

    .

    5.2 ( )

    (5.1) ( ) 2,NE

    1( ) ( ) ( )NE S E N E x 2

    1 1( ) ( ) ( ) ( )Nv r S v r N E x E N v r x

  • 65

    5.2 Poisson

    Poisson

    .

    Poisson

    .

    0,1

    .

    , nk 1 np

    1,

    n n 1,...,n .

    .

    n

    n pn:

    ( ) (1 ) , 0,...,nn n nn

    P N p p n

    ( )

    0

    ( ) ( ) ( )NS N N

    F x P S x p x

    .

    n lim 0nn

    np ,

    lim ( ) , 0,1,2,...nn

    P N e

  • 66

    5.2 ( Poisson)

    ( , ), 1,...,iN i i

    S CPoi i d

    , 1

    ( , )i

    d

    N Ni

    S S CPoi ,

    1

    d

    ii

    1

    di

    ii

    5.3

    .

    NS

    F

    , .

    .

    Poisson ( , )nS CPoi .

    NS

    F

    NS

    F .

    : iX (

    ) NS iX . :

    1

    2

    1 1

    ( ) ( ) ( )( )

    ( )( ) ( ) ( ) ( )

    N

    N NS

    N

    S E S x E N E XF x

    v r Sv r N E X E N v r X

    : NS k Y ,

    k ( , )Y . (k, , )

    , k Y

    NS , :

  • 67

    1( )k E X 212

    ( )E X

    31

    321

    ( )2

    ( )

    E X

    E X

    .

    .

    Figure 10.4: Simulated CPoi(100,Exp(1)) data together with normal- and translated- gamma

    approximations (log-log scale). The 99.9% quantile estimates are also given.

    10.4 120x .

    90% NS

    F .

    .

    .

    5.4 Paujer

    .

  • 68

    1x

    1 0( ) 1P x 1( )g P x , ( )P P N .

    0 0g ( )

    1( ... )n

    ig P x x ,

    g .

    1( 1) ( )

    1

    n ni

    i

    g g g .

    :

    0 0( 0) ( 0)NS P S P N P (5.3)

    ( )

    1

    ( ) , 1n N nS P S n p g n

    (5.7) ( )ng .

    (5.3)

    .

    (5.4) ( Paujer): (p)

    Paujer (, b) ,b , :

    1r r

    bp P

    r 1r .

    : ( , )N B n P

    (1 )r n rrn

    p p pr

    0 r n

    1

    ( 1)

    1 (1 )r

    r

    P p n P

    P p r p

    Paujer (,b) 1

    p

    p

    ( 1)

    (1 )

    n Pb

    p

  • 69

    5.4 ( Paujer)

    Paujer(,b) 0 1( 0) 0g P x ,

    0 0S P 1, 11

    ri

    r i ri

    bS g S .

    5.5 Poisson

    Poisson ( , )CPoi ( )N Poi

    F . Poisson

    ( ) ( )v r N E N ,

    ( ) ( )v r N E N

    .

    ( )F .

    0 0( ) ( ) ( ) ( ) ( )NP P N P N dF e dF

    5.5 ( Poisson).

    0

    ( ) ( )NP e dF

    Poisson F .

    5.5: Poisson

    F . ( ) ( )E N E ( ) ( ) ( )v r N E v r .

  • 70

    5.6 ( Poisson)

    Poisson

    ( , ) .

    ( , )1

    N NB

    5.6 Poisson

    [0,1].

    , (t)

    [0,t] 0t .

    (t), 0t

    .

    5.6 ( ). 0

    ( )t

    N N t

    , 0 1 20, , ,...T T T

    1

    ( )kT t

    N t I .

    5.7 ( Poisson).

    0

    ( )t

    N N t Poisson

    >0 :

    i)

    ii) (0)=0 ,

    iii)

    iv) 0t , ( ) ( )N t Poi t

    5.6: iii) iv) 0 u t

    ()-(u) (t)-() 0 :

  • 71

    ( )( )

    ( ) ( ) ( ) uu

    P N N u P N u e

    ()-(u)

    (u,] (-u).

    5.6 ( Poisson).

    .

    .

    (1) Poisson >0

    (2)

    ( ) 1 0( )P N t t t , 0t

    ( ) 2 0( )P N t t , 0t

    (3) 1 1

    ( )Exp .

    (4) 0t , ( ) ( )N t Poi t ( )N t ,

    1 2, ,...,T T T

    .

    1 1, , / ( ) 1 0 ...

    ( , , )T T N t t t tf t t It

  • 72

    5.7 Poisson

    Poisson ,

    .

    5.7 (- Poisson). -

    Poisson , ( ) 0s , :

    i) (0) 0N

    ii) N

    iii) 0t ( ) ( ) 1 ( ) 0( )P N t h N t t h h , 0h

    ( ) ( ) 2 0( )P N t h N t h , 0h

    5.7 ( , ). -

    Poisson 0t

    1( ) ( )N t N t , N Poisson.

    N , .

  • 73

    Quantitative Risk Management(Concepts,Techniques and Tools)

    McNeil J. A. ,Frey R.,Embrechts P. ,Princeton University Press

    Brown ,Revuz D.,Yor M. , . , Leader Books(2004)

    Default risk insurance and incomplete market ,Mathematical Finance

    ,Artzner C. ,Delbaen F.,(1995)

    On the coherence of expected shortfall,Journal of Banking and

    Finance, Acerbi C.,Tasche D.(2002)

    Statistical Models Based on Counting Processes,Andersen P.,Gill

    R.,Keiding N.,Springer(1993)

    Market Models ,A Guide to Financial Data Analysis,Alexander

    C.,Wiley,(2001)