In
this article B. Gross is moving fast back and forth with this fat-tail
talk. It was not a comfortable read for me.
Some of it comes from the real depressing content.
I am trying to bring it
together in my mind; this immediate financial past as we understand it and what
is to come, all fat-tail driven.
In standard normal
distributions bulk of the incidents happen in the main body of the curve. But
really juicy, rare happenings are exiled to the extreme tails. As life goes on, distributions change without
any warning, randomness is the operative mode. The main body of the
distribution becomes less, as the fat from main body flows towards the tails: Thereby
the “fat-tails”. That means that the extreme events happen more often. As the
events of 1987, 2000, 2007 showed us brutally. We later decided in retro that
we now have better understanding of these events. I doubt it.
After all, the extreme tails
suppose to retain some of the characteristics of the initial distribution. I
always thought that this is what they mean by claiming that “markets have some
memory”. The problem I have been tackling for some time is the process of
remembrance. Why and how is it that market remembers? Why only a tiny, insignificant part of the market
remembered 1929 vividly in the summer of 1987.
Even though I have detailed understanding
and deep knowledge of memory formation in Computer Architectures as to how
memory starts, enhanced and finally erased. I practically have very limited
knowledge of memory formation and access methods in my brain and in markets as
well. I am reading Daniel Kahneman, hoping
to gain more understanding than ennui, tune in later...
Higher order moments
(skewness and kurtosis) of normal distribution give additional knowledge. But I
am not sure we can reliably determine market’s higher order moments. When we
are able to do it with some certainty it is too late.
I still like most of what he
is saying and probably agree with most of the end results. Yet, I am not sure
about the path to that ending. Between now and then there are thousands of possible
paths and we don’t know which one will be.
Doris Day was right: Que Sera Sera.