Myths of "Practice". A short discussion with a guy from MSCI Barra a few months ago revealed something quite interesting about these products. Unfortunately, I am not allowed to cite him. Only 1 thing, they are smart but not necessarily more intelligent than anyone out there. Simply put, necessary evils (personal views) :))
Today, during the presentation of my friend, I suddenly think of these models. A night playing a bit with the maths (and online games) leads me to some insights and more puzzles.
I call these "Myths" since I read somewhere that a myth is a story with purpose, trying to describe how the world works. So models of firms like MSCI Barra tend to perform as myths in some ways.