Optimizing Optimization: The Next Generation of Optimization Applications and Theory (Quantitative Finance)

(Romina) #1

Some properties of averaging simulated optimization methods 239


where


QR RˆK(ˆ,μμ)Ωˆ^1 (ˆ, )

with


QWTNKˆ (,)
T
KK^1  1  QK^1

1


Following earlier results, we now define:

hQˆ (,)ˆ (,)
KK
10 ^110

and we have immediately, corresponding to Equation (10.7):


ˆ ()
(,(/))

hK TNK
NKThK



χ
χ

2
2




where hQKK(, )’^1 (, )10 with Q (^10) K  ( μ ,R ) Ω ^1 ( μ ,R ).
Thus , by a simple substitution into our earlier results, we can readily spec-
ify the exact distribution and moments of αˆ,IR, and TE. That is, we merely
replace N  1 by N  K and h by h K. As intuition suggests, increasing the
number of restrictions is exactly the same as reducing the number of assets.
However, the noncentrality parameter h K will change as the constraints change.
This is clear from the following. If we let:
R
r
r
r
KN
K


1
2


⎜⎜
⎜⎜
⎜⎜
⎜⎜
⎜⎜


⎟⎟
⎟⎟
⎟⎟
⎟⎟
⎟⎟
⎟ where r 1 is a 1  N vector.
Then,
Q
R
RRR
a
K
K




μμμ
μ
ββ β
β
ΩΩ
Ω
11
11
11
Ω









γγγ γ
βγ γ
β
β
(^1 121)
K
KK KK
a

















ΓΓ








and h K will be the (1,1)-th element of the inverse of the ( K  1)-th principal
minor of Q K.
That is,
haK
()ββΓ^11

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