From "Strategic Humor" in HBR Sep-10 . We, lumberjacks, could if we should - To Tree Or Not To Tree ;)
This has a serious background, because we still find tree based methods even in newer quant finance presentations nad discussions. To make no mistake, tree-based methods are great for understanding, say, the option theory, but they are firewood if applied as solvers of complex financial PDEs.
The Evermore Working and Frequently Updated FACTORY
Do We All Need To Become Philosophers?
In my first short post about The Blank Swan , see The Market Of The Future, ... I mentioned that I find the thoughts behind this book present such a revolutionary way of treating derivatives pricing and technology that I placed it on the shelf with the books that influenced my thinking most.
Shanghai - the city that never sleeps
When I arrived in Shanghai, I thought "There is so much life in this city." People doing their businesses, thousands of busses at the EXPO parking area, a hotel dedicated to service their customers at the highest level, and Shawn Liu and his team having organised a perfect event for the following day.
Shanghai After Noon
The Blank Swan Of Free Metal Forming
The Problem
Take the process of free metal forming: you need to understand the framework of the elastoplasticity theory and the complexity and limits of its mathematics derived from the mathematics of continuum mechanics. Deformation is decomposed (replicated?) into elastic and plastic parts and for simplicity decompositions shall determine stress and kinematical quantities. However, resulting PDEs can be solved by finite element schemes. They "only" need to be calibrated related to the physical properties of the material that is dependent on recipes, and properties that are result of the process - like rolling and thermal treatment? And work as predictive models for shapes? If you buy a metal sheet you order it by standardized "names". And this is where the headache begins.The Solution
Standardized mass-steel allows ranges of physical properties of up to 15%. But each single sheet has its own metallurgical fingerprints. It is impossible, to measure the properties before bending, because you needed to destroy part of the sheet. So, you need to recalibrate your models during the forming process ("continuously"), say, by observing the force-at-angle trajectory over thprocess (transformed from a value that itself is not only a geometrical calculation, but dependent on material). For explanation of the quantified elastoplastic behavior in this step. The closer you come to the final shape the more your system knows about the concrete material and the better it can explain ....You could make continuous measurements of the shape? First, this has cost. Second, the material does not stay in the form you brought it by the machine, it uses its elasticity memory and reshapes.
As coal-faced mathematicians, we know, how to model, solve and recalibrate such processes - fast and accurate. With this respect metal forming dynamics is not so different from financial market dynamics. A concrete angle has been materialized from the many possible .... Sounds familiar?
Market Of The Future, Or Market With Future?
Yes, the thought behind the book is deeply challenging (Dan Tudball, Editor of Wilmott magazine). Ayache himself: I tend to only write the things that will be as difficult to read as they were to write. IMO, there is also an "economic aspect" of writing and reading and one might also think of the ink-factor one brings to reading. But this does not say anything about the quality which cannot be measured by operational semantics (like computational knowledge), only about my Blank Swans (as drawn in the picture here)
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