Staying ahead on downside risk 157
approach tends to underweight the asset compared to mean – variance. Once
again, the main differences are found for the S & P and FTSE indices. By adopt-
ing a mean – EVaR criterion instead of mean – variance, we end up overweighting
the UK index, for the reason explained above: The S & P 500 has experienced
Table 6.5 Actual returns observed for December 2008 and sample moments of the
100 simulated alpha vectors
spx dax nky ukx
Return in December 2008 2.20% 1.51% 3.70% 1.54%
Simulated alphas:
Mean 0.74% 0.45% 1.08% 0.40%
Standard deviation 2.08% 2.84% 2.88% 1.97%
80
60
40
20
0
80
60
40
20
0
Frequency
80
40
50
30
20
10
0
Frequency
E-VaR
overweight
Mean variance
overweight
–40 –20 0 20
dax ukx
nky spx
Pct points Pct points
Pct points Pct points
40 60 80 –40 -20 0 20 40 60 80
Frequency
35
25
30
20
15
5
10
0
Frequency
–40 –20 0 20 40 60 80 –40 –20 0 20 40 60 80
Figure 6.5 Difference between mean – variance and mean – EVaR allocation.