Following to my previous article posted on link: http://emfps.blogspot.com/2012/08/emfps-how-can-we-get-power-set-of-set.html,
let me tell you one of the applications of this method in Risk Management. In this article, I am willing to solve a case
in which the template is referred to my article of “EMFPS:
Efficient Portfolio of Assets (The Optimization for Risk, Return and
Probability)” posted on link:
http://emfps.blogspot.com/2011/10/emfps-efficient-portfolio-of-assets.html.
http://emfps.blogspot.com/2011/10/emfps-efficient-portfolio-of-assets.html.
The
Case: To Find Minimum Risk for Portfolio of Assets in Variety of the Outcomes
If we have
had a range of probability for our outcomes where there is not the same probability
assigned to the outcomes, how can we calculate minimum risk for the portfolio
of assets? What are the probability distributions assigned to the expected
portfolio return in which we will have minimum risk?
Let me
start the solution of this case by using of the example stated in article of “EMFPS: Efficient
Portfolio of Assets (The Optimization for Risk, Return and Probability)” posted
on link:
http://emfps.blogspot.com/2011/10/emfps-efficient-portfolio-of-assets.html as follows:
http://emfps.blogspot.com/2011/10/emfps-efficient-portfolio-of-assets.html as follows:
Referring
to step (3), I define the range of probability for six outcomes equal to 10% to
21%.
10% ≤ Pr
≤ 21%
The
solution is step by step below cited:
Ø
On the spreadsheet of excel, we should type:
A1
= p
A2
= 6
A3
= 0.1, A4, = 0.11, A5 = 0.12, A6 = 0.13, A7 = 0.14, A8 = 0.15, A9 = 0.16, A10 =
0.17
A11
= 0.18, A12 = 0.19, A13 = 0.2, A14 = 0.21
Ø
Using from VB code written
by Myrna Larson mentioned in article of “EMFPS:
How Can We Get the Power Set of a Set by Using of Excel?” posted on
link: http://emfps.blogspot.com/2012/08/emfps-how-can-we-get-power-set-of-set.html
Ø
We will have 665280 cells filled with different
permutations (please check it by formula = PERMUT (12,6) on excel)
Ø Due to each subsets is into one cell, to split the elements of
subsets into other cells, we should utilize Data Tab – Data Tools – Text to
Columns
Ø
Using from formula = =IF(SUM(A2:F2)=1,A2,"")
on excel to find all combinations of probabilities which are equal to 1or 100%.
Copy and paste this formula for all 665280 cells.
Ø
Using from formula: Rv= SUM [Rp(i) * P(i)] to
find the expected value of portfolio returns. Copy and paste this formula for
all 665280 cells.
Ø
Using from formula: Qr = {SUM [(Rp(i) – Rv)^2) * P(i)]}^0.5 to find Standard Deviation of the
expected portfolio returns. Copy and paste this formula for all 665280 cells.
Ø
Using from formula: CV = Qr / Rv to find Coefficient of
Variation. Copy and paste this formula for all 665280
cells.
Now, we
will be able to find the minimum Qr and CV for the range of 10% ≤ Pr ≤ 21% as
follows:
Qr(min)
|
0.1993867
|
CV(min)
|
0.0144341
|
There
are 12 combinations of the probability distributions (in the range of 10% to
21%) assigned to the outcomes which show us the minimum risk as follows:
C1
|
C2
|
C3
|
C4
|
C5
|
C6
|
|
Outcome (1)
|
0.21
|
0.21
|
0.21
|
0.21
|
0.21
|
0.21
|
Outcome (2)
|
0.18
|
0.18
|
0.18
|
0.18
|
0.19
|
0.19
|
Outcome (3)
|
0.19
|
0.19
|
0.2
|
0.2
|
0.18
|
0.18
|
Outcome (4)
|
0.2
|
0.2
|
0.19
|
0.19
|
0.2
|
0.2
|
Outcome (5)
|
0.1
|
0.12
|
0.1
|
0.12
|
0.1
|
0.12
|
Outcome (6)
|
0.12
|
0.1
|
0.12
|
0.1
|
0.12
|
0.1
|
|
(C1
to C12 are all 12 combinations)
What do
you think about using of my previous simulation model mentioned in article of “Application
of Pascal’s Triangular plus Monte Carlo Analysis to Find the Least Squares
Fitting for a Limited Area” posted on link: http://emfps.blogspot.com/2012/05/application-of-pascals-triangular-plus_23.html?
I have
already calculated the minimum risk by using of this simulation model. The
final results are as follows:
CV(min)
|
0.014946785
|
Qr(min)
|
0.206693106
|
As you
can see, the error is approximately equal to 3.6%.
How can
we decrease the error by using of this simulation model?
Definitely
we will be able to decrease the error by increasing the calculation iteration.
Note:
“All spreadsheets and calculation notes are available. The people, who are
interested in having my spreadsheets of this method as a template for further
practice, do not hesitate to ask me by sending an email to: soleimani_gh@hotmail.com or call
me on my cellphone: +989109250225. Please be informed these spreadsheets are
not free of charge.”
I don't understand exactly if the minimization of the portfolio risk is coherent with the Montecarlo method.
ReplyDeleteThe first fact is the expected value related to quadratic function; the second fact is a random choice. How those two facts are correlated?